Fair Value of Assets and Liabilities - Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents	$ 506,491	$ 283,524	$ 32,463
Carrying Value
Assets:
Cash and cash equivalents	506,491	283,524
Restricted cash and investments	41,831	28,329
Liabilities:
Borrowings under Senior Credit Facility	1,546,895	1,474,437
Non-recourse debt	310,108	344,614
Fair Value
Assets:
Cash and cash equivalents	506,491	283,524
Restricted cash and investments	41,831	28,329
Liabilities:
Borrowings under Senior Credit Facility	1,448,280	1,342,066
Non-recourse debt	310,108	344,632
5.125% Senior Notes due 2023 | Carrying Value
Liabilities:
Senior notes, fair value	259,275	281,783
5.125% Senior Notes due 2023 | Fair Value
Liabilities:
Senior notes, fair value	248,479	256,096
5.875% Senior Notes due 2024 | Carrying Value
Liabilities:
Senior notes, fair value	225,293	242,500
5.875% Senior Notes due 2024 | Fair Value
Liabilities:
Senior notes, fair value	199,522	202,458
6.00% Senior Notes due 2026 | Carrying Value
Liabilities:
Senior notes, fair value	350,000	350,000
6.00% Senior Notes due 2026 | Fair Value
Liabilities:
Senior notes, fair value	283,691	279,493
6.50% Exchangeable Senior Notes due 2026 | Carrying Value
Liabilities:
Senior notes, fair value	230,000
6.50% Exchangeable Senior Notes due 2026 | Fair Value
Liabilities:
Senior notes, fair value	248,211
5.875% Senior Notes due 2022 | Carrying Value
Liabilities:
Senior notes, fair value		193,958
5.875% Senior Notes due 2022 | Fair Value
Liabilities:
Senior notes, fair value		192,736
Quoted Prices in Active Markets (Level 1) | Fair Value
Assets:
Cash and cash equivalents	506,491	283,524
Restricted cash and investments	41,831	28,329
Significant Other Observable Inputs (Level 2) | Fair Value
Liabilities:
Borrowings under Senior Credit Facility	1,448,280	1,342,066
Non-recourse debt	310,108	344,632
Significant Other Observable Inputs (Level 2) | 5.125% Senior Notes due 2023 | Fair Value
Liabilities:
Senior notes, fair value	248,479	256,096
Significant Other Observable Inputs (Level 2) | 5.875% Senior Notes due 2024 | Fair Value
Liabilities:
Senior notes, fair value	199,522	202,458
Significant Other Observable Inputs (Level 2) | 6.00% Senior Notes due 2026 | Fair Value
Liabilities:
Senior notes, fair value	283,691	279,493
Significant Other Observable Inputs (Level 2) | 6.50% Exchangeable Senior Notes due 2026 | Fair Value
Liabilities:
Senior notes, fair value	$ 248,211
Significant Other Observable Inputs (Level 2) | 5.875% Senior Notes due 2022 | Fair Value
Liabilities:
Senior notes, fair value		$ 192,736