XML 94 R84.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Other Investments (Safehold Inc). (Details) $ / shares in Units, $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Nov. 30, 2021 USD ($) | Sep. 30, 2021 USD ($) shares | Jun. 30, 2021 USD ($) agreement | Feb. 28, 2021 USD ($) | Jan. 31, 2021 USD ($) | Nov. 30, 2020 USD ($) shares | Oct. 31, 2020 USD ($) | Sep. 30, 2020 USD ($) | Jun. 30, 2020 | Mar. 31, 2020 USD ($) shares | Nov. 30, 2019 USD ($) shares | Aug. 31, 2019 USD ($) shares | May 31, 2019 | Feb. 28, 2019 | Jan. 31, 2019 USD ($) director $ / shares shares | Oct. 31, 2017 USD ($) | Dec. 31, 2021 USD ($) $ / shares shares | Jun. 30, 2021 USD ($) | Dec. 31, 2021 USD ($) $ / shares shares | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Mar. 31, 2021 USD ($) | Aug. 31, 2017 USD ($)
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 51.90% |  | 51.90% |  |  |  |
Number of limited partnership units purchased (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 12,500,000 |  |  |  |  |  |  |  |
Investor units, purchase price per unit (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20.00 |  |  |  |  |  |  |  |
Cash investment in equity method investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 250,000 |  |  |  | $ 216,997 | $ 260,121 | $ 656,720 |  |
Conversion of stock |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |
Restriction period on common stock received as payment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 years |  |  |  |
Income from sales of real estate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 26,319 | 6,318 | 11,969 |  |
Payment to acquire purchase option agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000 |  |  |  |  |
Expenses incurred in acquisition of purchase option agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 200 |  |  |  |  |
SAFE |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ground lease term |  |  |  |  |  |  |  |  | 99 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sale of purchase option agreement |  |  | $ 1,200 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,200 |  |  |  |  |
Gain recognized on sale of purchase option agreement |  |  | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of agreements | agreement |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price per agreement for sale of land and related Ground Lease, subject to certain conditions being met | $ 33,300 |  | $ 42,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 42,000 |  |  |  |  |
Multiple required that may trigger receipt of additional consideration | 1.25 |  | 1.25 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.25 |  |  |  |  |
Percentage of required return on investment that may trigger receipt of additional consideration | 12.00% |  | 9.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | SAFE |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leasehold improvement allowance, Ground Leases | $ 51,800 |  | $ 83,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 83,000 |  |  |  |  |
Fee percent of SAFE Equity up to $1.5 billion |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee as percent of equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.00% |  |  |  |
Fee percent of SAFE Equity up to $1.5 billion | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee equity threshold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,500,000 |  | $ 1,500,000 |  |  |  |
Fee percent of SAFE Equity between $1.5 billion and $3.0 billion |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee as percent of equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.25% |  |  |  |
Fee percent of SAFE Equity between $1.5 billion and $3.0 billion | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee equity threshold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,000,000 |  | $ 3,000,000 |  |  |  |
Fee percent of SAFE Equity between $1.5 billion and $3.0 billion | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee equity threshold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,500,000 |  | $ 1,500,000 |  |  |  |
Fee percent of SAFE Equity between $3.0 billion and $5.0 billion |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee as percent of equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.375% |  |  |  |
Fee percent of SAFE Equity between $3.0 billion and $5.0 billion | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee equity threshold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,000,000 |  | $ 5,000,000 |  |  |  |
Fee percent of SAFE Equity between $3.0 billion and $5.0 billion | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee equity threshold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,000,000 |  | $ 3,000,000 |  |  |  |
Fee percent of SAFE Equity over $5.0 billion |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee as percent of equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.50% |  |  |  |
Fee percent of SAFE Equity over $5.0 billion | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee equity threshold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,000,000 |  | $ 5,000,000 |  |  |  |
Safehold Inc. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase option, purchase price to acquire property |  |  | 215,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 215,000 |  |  |  |  |
Purchase option, square feet of future office space development |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,100 |  |  |  |  |
Real estate equity investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity method investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,230,511 |  | 1,230,511 | 1,027,651 |  |  |
Real estate equity investments | Safehold Inc. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management agreement, termination fee as multiple of prior year management fee |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 |  |  |  |  |  |  |  |
Safehold Inc. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash investment in equity method investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,800 |  | $ 69,500 |  |  |  |
Shares acquired (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 24,108 |  | 1,000,000.0 |  |  |  |
Average cost per share acquired | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 72.96 |  | $ 72.96 |  |  |  |
Average cost per share | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 73.86 |  | $ 73.86 |  |  |  |
Expense reimbursements from related party |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 7,500 | 5,000 | 2,100 |  |
Amount of loan funded |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 16,100 |
Income from sales of real estate |  | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Consideration received |  | 22,100 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ground lease term |  |  |  |  |  |  |  |  |  |  |  | 99 years |  | 98 years |  |  |  |  |  |  |  |  |
Safehold Inc. | Management Fees |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management fee revenue from related party |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 14,900 | 12,700 | 7,500 |  |
Safehold Inc. | Real estate equity investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 64.60% |  | 64.60% |  |  |  |
Voting power cap threshold |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 41.90% |  |  |  |  |  |  |  |
Number of director nominees | director |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 |  |  |  |  |  |  |  |
Equity method investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,168,532 |  | $ 1,168,532 | 937,712 |  |  |
Safehold Inc. | Real estate equity investments | Private Placement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash investment in equity method investments |  | $ 50,000 |  |  |  | $ 65,000 |  |  |  | $ 80,000 | $ 130,000 | $ 168,000 |  |  |  |  |  |  |  |  |  |  |
Shares acquired (in shares) | shares |  | 657,894 |  |  |  | 1,100,000 |  |  |  | 1,700,000 | 3,800,000 | 6,000,000.0 |  |  |  |  |  |  |  |  |  |  |
Multifamily Development San Jose |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leasehold improvement allowance, Ground Leases |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 7,200 |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300 | 3,400 | 1,200 |  |
Proceeds from sale of ground lease |  |  |  |  |  |  |  | $ 34,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) from sale of ground lease |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6,100 |  |  |
Ground lease term |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 99 years |  |  |  |  |  |  |
Multifamily Development San Jose | Leasehold First Mortgage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment to provide loan to lessee |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 80,500 |  |  |  |  |  |  |
Carrying value of loans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 80,500 |  |  |  |  |  |  |
Ground Lease, Washington DC building conversion |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment to provide loan to lessee |  |  |  |  |  |  | $ 22,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 300 |  |  |
Consideration received |  |  |  |  |  |  | $ 2,300 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Real Estate Equity Investment January 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest |  |  |  |  | 53.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity method investments |  |  |  |  | $ 63,300 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recognized gain or loss |  |  |  |  | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Real Estate Equity Investment September 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest |  | 53.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash investment in equity method investments |  | $ 2,700 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment to provide loan to lessee |  | 75,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Consideration received |  | 2,700 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multi-Family Project |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recognized gain or loss |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Hotel Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment to provide loan to lessee |  |  |  | $ 50,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,900 |  |  |  |
Consideration received |  |  |  | $ 1,900 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recognized gain or loss |  | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ground Lease, Atlanta medical office | SAFE |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment to provide loan to lessee |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 24,000
Interest income |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,200 |  |
Amount of loan funded |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 18,400
Land Parcel One | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leasehold improvement allowance, Ground Leases |  |  | 83,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 83,000 |  |  |  |  |
Land Parcel Two | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leasehold improvement allowance, Ground Leases |  |  | $ 83,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 83,000 |  |  |  |  |

X
- Definition Common Stock Received as Payment Restriction Period + References No definition available. + Details
Name: | star_CommonStockReceivedasPaymentRestrictionPeriod
Namespace Prefix: | star_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Common Stock, Voting Rights, Investor Units Voting Power Threshold + References No definition available. + Details
Name: | star_CommonStockVotingRightsInvestorUnitsVotingPowerThreshold
Namespace Prefix: | star_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Gain (Loss) From Sale Of Ground Lease + References No definition available. + Details
Name: | star_GainLossFromSaleOfGroundLease
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain (loss) recognized on sale of purchase option agreement. + References No definition available. + Details
Name: | star_GainLossOnSaleOfPurchaseOptionAgreement
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Ground Leases, Term + References No definition available. + Details
Name: | star_GroundLeasesTerm
Namespace Prefix: | star_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investor Units, Conversion Of Stock + References No definition available. + Details
Name: | star_InvestorUnitsConversionOfStock
Namespace Prefix: | star_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investor Units, Purchase Price Per Unit + References No definition available. + Details
Name: | star_InvestorUnitsPurchasePricePerUnit
Namespace Prefix: | star_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reflects the aggregate gross carrying amount of all categories of loans held in portfolio, after deducting deferred income, but before deducting the allowance for losses on loans. + References No definition available. + Details
Name: | star_LoansReceivableNetOfDeferredIncome
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of agreements entered into by the Company. + References No definition available. + Details
Name: | star_NumberOfAgreements
Namespace Prefix: | star_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Investor Units Purchased + References No definition available. + Details
Name: | star_NumberOfInvestorUnitsPurchased
Namespace Prefix: | star_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The square footage of future office space development associated with a purchase option agreement. + References No definition available. + Details
Name: | star_OptionAgreementFutureOfficeSpaceDevelopmentSquareFeet
Namespace Prefix: | star_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of a purchase option agreement. + References No definition available. + Details
Name: | star_PaymentsToAcquirePurchaseOptionAgreement
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Proceeds From Sale Of Ground Lease + References No definition available. + Details
Name: | star_ProceedsFromSaleOfGroundLease
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow associated with the sale of purchase option agreement during the period. + References No definition available. + Details
Name: | star_ProceedsFromSalePurchaseOptionAgreement
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Average per share amount paid for shares of common stock purchased in a stock transaction in accordance with SEC Rules 10b5-1 and 10b-18. + References No definition available. + Details
Name: | star_PurchaseOfStockSecTradingPlanGuidelinesAveragePricePerShare
Namespace Prefix: | star_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Purchase price to acquire property under a purchase option agreement. + References No definition available. + Details
Name: | star_PurchaseOptionCostToAcquireProperty
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Real Estate, Leasehold Improvement Allowance + References No definition available. + Details
Name: | star_RealEstateLeaseholdImprovementAllowance
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Expenses incurred in relation to a real estate transaction. + References No definition available. + Details
Name: | star_RealEstateTransactionExpense
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Related Party Transaction, Commitment to Extend Credit, Amount Funded + References No definition available. + Details
Name: | star_RelatedPartyTransactionCommitmenttoExtendCreditAmountFunded
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Related Party Transaction, Commitment to Extend Credit to Customer + References No definition available. + Details
Name: | star_RelatedPartyTransactionCommitmenttoExtendCredittoCustomer
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Related Party Transaction, Loan, Consideration Received + References No definition available. + Details
Name: | star_RelatedPartyTransactionLoanConsiderationReceived
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Related Party Transaction, Management Agreement, Renewal Clause, Termination Fee As Multiple Of Prior Year Management Fee + References No definition available. + Details
Name: | star_RelatedPartyTransactionManagementAgreementRenewalClauseTerminationFeeAsMultipleOfPriorYearManagementFee
Namespace Prefix: | star_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Related Party Transaction, Management Fee, Percent of Equity + References No definition available. + Details
Name: | star_RelatedPartyTransactionManagementFeePercentofEquity
Namespace Prefix: | star_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Related Party Transaction, Management Fee, Shareholders' Equity Threshold Amount + References No definition available. + Details
Name: | star_RelatedPartyTransactionManagementFeeShareholdersEquityThresholdAmount
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The multiple required that may trigger receipt of additional consideration. + References No definition available. + Details
Name: | star_SaleOfPropertyAndGroundLeaseRequiredMultiple
Namespace Prefix: | star_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of required return on investment that may trigger receipt of additional consideration. + References No definition available. + Details
Name: | star_SaleOfPropertyAndGroundLeaseRequiredPercentageReturnOnInvestment
Namespace Prefix: | star_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sale price per agreement for sale of land and related Ground Lease, subject to certain conditions being met. + References No definition available. + Details
Name: | star_SaleOfPropertyAndGroundLeaseSubjectToCertainConditionsSalesPricePerAgreemen
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Stockholders Agreement, Director Nominees + References No definition available. + Details
Name: | star_StockholdersAgreementDirectorNominees
Namespace Prefix: | star_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of gain (loss) on sale of financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107425-111719 + Details
Name: | us-gaap_GainLossOnSaleOfNotesReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=123351718&loc=d3e2443-110228 + Details
Name: | us-gaap_GainLossOnSaleOfProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of interest income earned from interest-bearing assets owed to the entity by related party. + References No definition available. + Details
Name: | us-gaap_InterestIncomeRelatedParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the sum of all other revenue and income realized from sales and other transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period. + References No definition available. + Details
Name: | us-gaap_RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07.1(c)) -URI http://asc.fasb.org/extlink&oid=120401555&loc=SL114874292-224272 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(B)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(C)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1(e)) -URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227 + Details
Name: | us-gaap_RevenueFromRelatedParties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The number of shares issued or sold by the subsidiary or equity method investee per stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | star_ManagementAgreementFeeStructureAxis=star_ManagementFeeTrancheOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | star_ManagementAgreementFeeStructureAxis=star_ManagementFeeTrancheTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | star_ManagementAgreementFeeStructureAxis=star_ManagementFeeTrancheThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | star_ManagementAgreementFeeStructureAxis=star_ManagementFeeTrancheFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=star_SafeholdInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_RealEstateInvestmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_SafeholdInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ManagementServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_GroundLeaseMultifamilyDevelopmentSanJoseCAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_LeaseholdFirstMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_GroundLeaseConversionWashingtonDCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_OtherRealEstateEquityInvestmentJanuary2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_OtherRealEstateEquityInvestmentSeptember2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_MultiFamilyProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_HotelPropertyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=star_GroundLeaseAtlantaMedicalCenterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AssetAcquisitionAxis=star_LandParcelOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AssetAcquisitionAxis=star_LandParcelTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |