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Debt Obligations, net - Schedule of Debt (Details) - USD ($) | 1 Months Ended | 3 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2019 | Jun. 30, 2018 | Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2019 | Nov. 30, 2019 | Oct. 31, 2017 | Sep. 30, 2017
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 3,628,584,000 |  | $ 3,436,038,000 |  |  |
Debt discounts and deferred financing costs, net |  |  | (45,224,000) |  | (48,958,000) |  |  |
Debt obligations, net |  |  | 3,583,360,000 |  | 3,387,080,000 |  |  |
Interest costs capitalized |  |  | $ 500,000 | $ 3,000,000.0 |  |  |  |
Senior Term Loan | LIBOR |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 1.00% |  |  |  |  |
3.125% senior convertible notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Stated interest rates (as a percent) |  |  |  | 3.125% |  |  |  |
Secured credit facilities and mortgages |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 1,516,084,000 |  | 1,212,993,000 |  |  |
Debt discounts and deferred financing costs, net |  |  | (7,309,000) |  |  |  |  |
Debt obligations, net |  |  | 1,508,775,000 |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 300,000,000 |  | 0 |  |  |
Debt instrument term (in years) |  |  | 1 year |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | Federal Funds Rate |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 0.50% |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | LIBOR |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 2.00% |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | LIBOR | Minimum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) | 2.00% |  | 1.00% |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | LIBOR | Minimum | Interest Rate Category Two |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 2.00% |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | LIBOR | Maximum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) | 2.50% |  |  |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | LIBOR | Maximum | Interest Rate Category Two |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 2.50% |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | Base Rate | Minimum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) | 1.00% |  |  |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | Base Rate | Minimum | Interest Rate Category One |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 1.00% |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | Base Rate | Maximum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) | 1.50% |  |  |  |  |  |  |
Secured credit facilities and mortgages | Revolving Credit Facility | Base Rate | Maximum | Interest Rate Category One |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 1.50% |  |  |  |  |
Secured credit facilities and mortgages | Senior Term Loan |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 491,875,000 |  | 491,875,000 |  |  |
Debt instrument, face amount |  | $ 650,000,000.0 |  |  |  |  |  |
Secured credit facilities and mortgages | Senior Term Loan | Federal Funds Rate |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 0.50% |  |  |  |  |
Secured credit facilities and mortgages | Senior Term Loan | LIBOR |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  | 2.75% | 2.75% |  |  |  |  |
Secured credit facilities and mortgages | Senior Term Loan | LIBOR | Maximum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 1.75% |  |  |  |  |
Secured credit facilities and mortgages | Mortgages collateralized by net lease assets |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 724,209,000 |  | 721,118,000 |  |  |
Weighted average interest rate (percent) |  |  | 4.40% |  |  |  |  |
Secured credit facilities and mortgages | Mortgages collateralized by net lease assets | Minimum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Stated interest rates (as a percent) |  |  | 2.54% |  |  |  |  |
Secured credit facilities and mortgages | Mortgages collateralized by net lease assets | Maximum |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Stated interest rates (as a percent) |  |  | 7.26% |  |  |  |  |
Unsecured notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 2,012,500,000 |  | 2,123,045,000 |  |  |
Unsecured notes | 6.00% senior notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | 0 |  | $ 110,545,000 |  |  |
Stated interest rates (as a percent) |  |  |  |  | 6.00% |  |  |
Unsecured notes | 5.25% senior notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 400,000,000 |  | $ 400,000,000 |  |  |
Stated interest rates (as a percent) |  |  | 5.25% |  |  |  |  |
Unsecured notes | 3.125% senior convertible notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 287,500,000 |  | 287,500,000 |  |  |
Debt obligations, net |  |  | $ 270,200,000 |  | 268,700,000 |  |  |
Stated interest rates (as a percent) |  |  | 3.125% |  |  |  | 3.125% |
Convertible debt, conversion ratio (in shares per par value) |  |  | 0.068342 |  |  |  |  |
Convertible debt, conversion ratio principal amount |  |  | $ 1,000 |  |  |  |  |
Convertible debt, conversion price (in dollars per share) |  |  | $ 14.63 |  |  |  |  |
Liability component of convertible debt |  |  |  |  |  |  | $ 34,000,000.0 | $ 221,800,000
Equity component of convertible debt |  |  |  |  |  |  | 3,400,000 | $ 22,500,000
Debt instrument, face amount |  |  |  |  |  |  | $ 37,500,000 |
Unamortized discount |  |  | $ 14,200,000 |  | 15,500,000 |  |  |
Contractual interest |  |  | 2,200,000 | $ 2,200,000 |  |  |  |
Amortization of debt discount |  |  | $ 1,300,000 | $ 1,200,000 |  |  |  |
Effective interest rate (percent) |  |  | 5.20% |  |  |  |  |
Unsecured notes | 4.75% senior notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 775,000,000 |  | 775,000,000 |  |  |
Stated interest rates (as a percent) | 4.75% |  | 4.75% |  |  | 4.75% |  |
Debt instrument, face amount | $ 675,000,000.0 |  |  |  |  | $ 100,000,000.0 |  |
Effective interest rate (percent) |  |  |  |  |  | 4.29% |  |
Unsecured notes | 4.25% senior notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 550,000,000 |  | $ 550,000,000 |  |  |
Stated interest rates (as a percent) |  |  | 4.25% |  | 4.25% |  |  |
Debt instrument, face amount |  |  |  |  | $ 550,000,000.0 |  |  |
Other debt obligations | Trust preferred securities |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Total debt obligations |  |  | $ 100,000,000 |  | $ 100,000,000 |  |  |
Other debt obligations | Trust preferred securities | LIBOR |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Basis point spread on variable interest rate (as a percent) |  |  | 1.50% |  |  |  |  |

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- Definition Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 + Details
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- Definition Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 2: 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(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 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(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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