XML 111 R84.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Debt Obligations, net (Narrative) (Details) shares in Millions | 1 Months Ended | 6 Months Ended | 7 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2017 USD ($) | Mar. 31, 2017 USD ($) property | Jan. 31, 2017 USD ($) | Nov. 30, 2016 USD ($) shares | Mar. 31, 2016 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Oct. 31, 2017 USD ($) | Aug. 31, 2016 USD ($) | Jun. 30, 2016 USD ($) | Mar. 31, 2015 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase of weighted average debt maturity |  |  |  |  |  | 1 year 6 months |  |  |  |  |  |  |  |
Weighted average debt maturity |  |  |  |  |  | 4 years |  |  |  |  |  |  |  |
Repayment of principal amount |  |  |  |  |  |  |  | $ 1,915,052,000 | $ 1,437,557,000 | $ 432,383,000 |  |  |  |
Loss on early extinguishment of debt, net |  |  |  |  |  |  |  | 14,724,000 | 1,619,000 | 281,000 |  |  |  |
Conversion of senior unsecured convertible notes into common stock |  |  |  |  |  |  |  | $ 0 | 9,596,000 | $ 0 |  |  |  |
2017 Secured Financing |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  | $ 227,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  | 3.795% |  |  |  |  |  |  |  |  |  |  |  |
Number of properties collateralizing loan | property |  | 12 |  |  |  |  |  |  |  |  |  |  |  |
Debt issuance costs |  | $ 7,300,000 |  |  |  |  |  |  |  |  |  |  |  |
2016 Senior Secured Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount | $ 400,000,000.0 |  |  |  |  |  |  |  |  |  |  | $ 500,000,000.0 | $ 450,000,000.0 |
Debt issuance costs | $ 2,600,000 |  |  |  |  |  | $ 6,200,000 |  | 6,200,000 |  |  |  |  |
Percentage of par credit facilities were issued at |  |  |  |  |  |  |  |  |  |  |  |  | 99.00% |
Variable interest rate, spread (as a percent) |  |  |  |  |  |  |  | 1.00% |  |  |  |  |  |
Price reduction (as a percent) | 1.50% |  |  |  |  |  |  |  |  |  |  |  |  |
Multiple of the minimum collateral coverage on outstanding borrowings |  |  |  |  |  | 1.25 |  | 1.25 |  |  |  |  |  |
Periodic principal payment (as a percent) |  |  |  |  |  |  |  | 0.25% |  |  |  |  |  |
Lender fees |  |  |  |  |  |  | 4,500,000 |  |  |  |  |  |  |
Third party fees capitalized |  |  |  |  |  |  | $ 4,300,000 |  |  |  |  |  |  |
Noncash debt issuance costs |  |  | $ 800,000 |  |  |  |  |  |  |  |  |  |  |
2016 Senior Secured Credit Facility | London Interbank Offered Rate (LIBOR) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate, spread (as a percent) | 3.00% |  | 3.75% |  |  |  | 4.50% | 3.00% |  |  |  |  |  |
2016 Senior Secured Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate, spread (as a percent) | 0.75% |  | 1.00% |  |  |  | 1.00% | 0.75% |  |  |  |  |  |
2016 Senior Secured Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate, spread (as a percent) |  |  |  |  |  |  |  | 2.00% |  |  |  |  |  |
2015 Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 250,000,000.0
Repayment of principal amount |  |  |  |  | $ 5,000,000 |  |  |  |  |  |  |  |  |
2015 $325 Million Secured Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  | $ 325,000,000 |  | $ 325,000,000 |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  | $ 325,000,000.0 |  | $ 325,000,000.0 |  |  |  |  |  |
2015 $325 Million Secured Revolving Credit Facility | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment fee percentage | 0.30% |  |  |  |  |  |  |  |  |  |  |  |  |
2015 $325 Million Secured Revolving Credit Facility | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment fee percentage | 0.50% |  |  |  |  |  |  |  |  |  |  |  |  |
2015 $325 Million Secured Revolving Credit Facility | London Interbank Offered Rate (LIBOR) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate, spread (as a percent) |  |  |  |  |  |  |  | 2.50% |  |  |  |  |  |
2015 $325 Million Secured Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate, spread (as a percent) |  |  |  |  |  |  |  | 1.00% |  |  |  |  |  |
4.625% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount | $ 400,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 4.625% |  |  |  |  | 4.625% |  | 4.625% |  |  |  |  |  |
5.25% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 5.25% |  |  |  |  | 5.25% |  | 5.25% |  |  |  |  |  |
3.125% senior convertible notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount | $ 250,000,000.0 |  |  |  |  |  |  |  |  |  | $ 37,500,000 |  |  |
Stated interest rate (as a percent) | 3.125% |  |  |  |  | 3.125% |  | 3.125% |  |  |  |  |  |
Unsecured Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt issuance costs | $ 18,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt, net |  |  |  |  |  |  |  | $ 13,600,000 | $ 400,000 |  |  |  |  |
4.00% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 4.00% |  |  |  |  | 4.00% |  | 4.00% |  |  |  |  |  |
Extinguishment of debt | $ 550,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
7.125% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 7.125% |  |  |  |  | 7.125% |  | 7.125% |  |  |  |  |  |
Extinguishment of debt | $ 300,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
4.875% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 4.875% |  |  |  |  | 4.875% |  | 4.875% |  |  |  |  |  |
Extinguishment of debt | $ 300,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
6.00% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  | $ 375,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  | 6.00% |  |  |  | 6.00% |  | 6.00% |  |  |  |  |  |
5.85% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  | 5.85% |  |  |  | 5.85% |  | 5.85% |  |  |  |  |  |
Extinguishment of debt |  | $ 99,700,000 |  |  |  |  |  |  |  |  |  |  |  |
9.00% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  | 9.00% |  |  |  | 9.00% |  | 9.00% |  |  |  |  |  |
Extinguishment of debt |  | $ 275,000,000 |  |  |  |  |  |  |  |  |  |  |  |
5.875% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  |  |  |  | 5.875% |  |  |  |  |  |  |  |  |
Extinguishment of debt |  |  |  |  | $ 261,400,000 |  |  |  |  |  |  |  |  |
6.50% senior notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  | $ 275,000,000 |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  |  |  |  | 6.50% | 6.50% |  | 6.50% |  |  |  |  |  |
Unsecured Notes 3.875 Percent Senior Notes Due July 2016 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Extinguishment of debt |  |  |  |  | $ 265,000,000 |  |  |  |  |  |  |  |  |
3.00% senior convertible notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  |  |  | 3.00% |  |  |  |  |  |  |  |  |  |
Repayment of principal amount |  |  |  | $ 200,000,000 |  |  |  |  |  |  |  |  |  |
Conversion of senior unsecured convertible notes into common stock |  |  |  | $ 9,600,000 |  |  |  |  |  |  |  |  |  |
Shares of common stock converted (in shares) | shares |  |  |  | 0.8 |  |  |  |  |  |  |  |  |  |
Safety, Income and Growth, Inc. | 2017 Secured Financing |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recourse triggering event, equity capitalization amount | 500,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Recourse triggering event, net assets | 250,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Other Expense | 2016 Senior Secured Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lender fees | 1,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Third party fees recognized | $ 1,500,000 |  |  |  |  |  | $ 1,900,000 |  |  |  |  |  |  |
Loss on early extinguishment of debt, net |  |  |  |  |  |  |  | $ 800,000 |  |  |  |  |  |

X
- Definition Represents the multiple of the minimum collateral coverage on outstanding borrowings required under the terms of the debt covenant. + References No definition available. + Details
Name: | star_DebtInstrumentCovenantMultipleofMinimumCollateralCoverageonOutstandingBorrowings
Namespace Prefix: | star_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Debt Instrument, Increase of Weighted Average Debt Maturity + References No definition available. + Details
Name: | star_DebtInstrumentIncreaseofWeightedAverageDebtMaturity
Namespace Prefix: | star_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Lender Fees, Amount + References No definition available. + Details
Name: | star_DebtInstrumentLenderFeesAmount
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Debt Instrument, Number of Properties Collateralizing Loan + References No definition available. + Details
Name: | star_DebtInstrumentNumberofPropertiesCollateralizingLoan
Namespace Prefix: | star_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Periodic Principal Payment, Percent + References No definition available. + Details
Name: | star_DebtInstrumentPeriodicPrincipalPaymentPercent
Namespace Prefix: | star_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Price Reduction, Percent + References No definition available. + Details
Name: | star_DebtInstrumentPriceReductionPercent
Namespace Prefix: | star_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Third Party Fees, Amount Capitalized + References No definition available. + Details
Name: | star_DebtInstrumentThirdPartyFeesAmountCapitalized
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Debt Instrument, Third Party Fees, Amount Recognized + References No definition available. + Details
Name: | star_DebtInstrumentThirdPartyFeesAmountRecognized
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Debt Instrument, Weighted Average Debt Maturity + References No definition available. + Details
Name: | star_DebtInstrumentWeightedAverageDebtMaturity
Namespace Prefix: | star_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Guarantor Obligations, Recourse Triggering Event, Equity Capitalization Amount + References No definition available. + Details
Name: | star_GuarantorObligationsRecourseTriggeringEventEquityCapitalizationAmount
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Guarantor Obligations, Recourse Triggering Event, Net Assets + References No definition available. + Details
Name: | star_GuarantorObligationsRecourseTriggeringEventNetAssets
Namespace Prefix: | star_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the percentage of principal amount used in the computation of issue price for the line of credit facility. + References No definition available. + Details
Name: | star_LineOfCreditFacilityIssuePriceAsPercentageOfPrincipalAmount
Namespace Prefix: | star_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 + Details
Name: | us-gaap_DebtConversionConvertedInstrumentAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 + Details
Name: | us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of debt issuance costs that were incurred during a noncash or partial noncash transaction. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586 + Details
Name: | us-gaap_DebtIssuanceCostsIncurredDuringNoncashOrPartialNoncashTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399 + Details
Name: | us-gaap_DeferredFinanceCostsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Gross amount of debt extinguished. + References No definition available. + Details
Name: | us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629 + Details
Name: | us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility. + References No definition available. + Details
Name: | us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. + References No definition available. + Details
Name: | us-gaap_RepaymentsOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_A2017SecuredFinancingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_A2016SeniorSecuredCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_SecuredCreditFacilityRevolverDueMarch2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_SecuredRevolvingCreditFacilityDueSeptember2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_Unsecured4.625SeniorNotesDueSeptember2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_Unsecured5.25SeniorNotesDueSeptember2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_Unsecured3.125SeniorConvertibleNotesDueSeptember2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotesFourPercentSeniorNotesDueNovember2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotesSevenPointOneTwoFivePercentSeniorNotesDueFebruary2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotes4point875PercentSeniorNotesDueJuly2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredSixPercentSeniorNotesDueApril2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotes5Point85PercentSeniorNotesDueMarch2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotesNinePercentSeniorNotesDueJune2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotes5Point875PercentSeniorNotesDueMarch2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotesSixPointFivePercentSeniorNotesDueJuly2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_UnsecuredNotes3point875PercentSeniorNotesDueJuly2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=star_SeniorConvertibleThreePointZeroPercentNotesDueNovember2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |