Convertible and Long-Term Debt Obligations - Summary of Debt (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 9,992,421	$ 7,511,760
Net Carrying Value, Current	375,506	1,114,652
Net Carrying Value, Long - Term	9,049,729	5,892,016
Unused Committed Amount	779,137	858,959
Solar Asset-backed notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long - Term	422,730	442,764
Solar Loan-backed Notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long - Term	236,726	137,024
Recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	7,410,395	5,102,844
Net Carrying Value, Current	136,442	761,293
Net Carrying Value, Long - Term	6,749,742	3,869,594
Unused Committed Amount	535,095	205,305
Recourse debt [Member] | 1.50% Convertible Senior Notes due in 2018 ("2018 Notes") [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	17,512	205,013
Net Carrying Value, Current	$ 17,155	$ 196,229
Interest Rate	1.50%	1.50%
Maturity Dates	Jun. 30, 2018	Jun. 30, 2018
Recourse debt [Member] | 0.25% Convertible Senior Notes due in 2019 ("2019 Notes") [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 920,000	$ 920,000
Net Carrying Value, Long - Term	$ 858,449	$ 827,620
Interest Rate	0.25%	0.25%
Maturity Dates	Mar. 31, 2019	Mar. 31, 2019
Recourse debt [Member] | 1.25% Convertible Senior Notes due in 2021 ("2021 Notes") [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 1,380,000	$ 1,380,000
Net Carrying Value, Long - Term	$ 1,172,195	$ 1,132,029
Interest Rate	1.25%	1.25%
Maturity Dates	Mar. 31, 2021	Mar. 31, 2021
Recourse debt [Member] | 2.375% Convertible Senior Notes due in 2022 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 977,500
Net Carrying Value, Long - Term	$ 834,834
Interest Rate	2.375%
Maturity Dates	Mar. 31, 2022
Recourse debt [Member] | 5.30% Senior Notes due in 2025 ("2025 Notes") [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 1,800,000
Net Carrying Value, Long - Term	$ 1,774,742
Interest Rate	5.30%
Maturity Dates	Aug. 31, 2025
Recourse debt [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 1,269,000	$ 969,000
Net Carrying Value, Long - Term	1,269,000	969,000
Unused Committed Amount	$ 535,095	$ 181,000
Debt instrument interest rate description	1% plus LIBOR	1% plus LIBOR
Maturity Dates	Jun. 30, 2020	Jun. 30, 2020
Recourse debt [Member] | Vehicle and Other Loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 15,367	$ 23,771
Net Carrying Value, Current	12,863	17,235
Net Carrying Value, Long - Term	$ 2,504	$ 6,536
Maturity Date, Start	Oct. 31, 2017	Mar. 31, 2017
Maturity Date, End	Sep. 30, 2019	Jun. 30, 2019
Recourse debt [Member] | Related Party Promissory Notes due in February 2018 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 100,000
Net Carrying Value, Current	$ 100,000
Interest Rate	6.50%
Maturity Dates	Feb. 28, 2018
Recourse debt [Member] | 2.75% Convertible Senior Notes due in 2018 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 230,000	$ 230,000
Net Carrying Value, Long - Term	$ 221,166	$ 212,223
Interest Rate	2.75%	2.75%
Maturity Dates	Nov. 30, 2018	Nov. 30, 2018
Recourse debt [Member] | 1.625% Convertible Senior Notes due in 2019 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 566,000	$ 566,000
Net Carrying Value, Long - Term	$ 506,535	$ 483,820
Interest Rate	1.625%	1.625%
Maturity Dates	Nov. 30, 2019	Nov. 30, 2019
Recourse debt [Member] | Zero-coupon Convertible Senior Notes due in 2020 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 103,000	$ 113,000
Net Carrying Value, Long - Term	$ 85,182	$ 89,418
Interest Rate	0.00%	0.00%
Maturity Dates	Dec. 31, 2020	Dec. 31, 2020
Recourse debt [Member] | Solar Bonds [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 32,016	$ 332,060
Net Carrying Value, Current	6,424	181,582
Net Carrying Value, Long - Term	$ 25,135	$ 148,948
Maturity Date, Start	Mar. 31, 2018	Jan. 31, 2017
Maturity Date, End	Jan. 31, 2031	Jan. 31, 2031
Recourse debt [Member] | Minimum [Member] | Vehicle and Other Loans [Member]
Debt Instrument [Line Items]
Interest Rate	1.80%	2.90%
Recourse debt [Member] | Minimum [Member] | Solar Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	2.60%	1.10%
Recourse debt [Member] | Maximum [Member] | Vehicle and Other Loans [Member]
Debt Instrument [Line Items]
Interest Rate	7.60%	7.60%
Recourse debt [Member] | Maximum [Member] | Solar Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	5.80%	6.50%
Non-recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 2,582,026	$ 2,408,916
Net Carrying Value, Current	239,064	353,359
Net Carrying Value, Long - Term	2,299,987	2,022,422
Unused Committed Amount	244,042	653,654
Non-recourse debt [Member] | Warehouse Agreements [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	556,992	390,000
Net Carrying Value, Current	154,191	73,708
Net Carrying Value, Long - Term	402,801	316,292
Unused Committed Amount	$ 43,008	$ 210,000
Interest Rate	2.70%
Debt instrument interest rate description		Various
Maturity Dates	Sep. 30, 2019	Sep. 30, 2018
Non-recourse debt [Member] | Canada Credit Facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 55,072	$ 67,342
Net Carrying Value, Current	21,357	18,489
Net Carrying Value, Long - Term	$ 33,715	$ 48,853
Maturity Dates	Dec. 31, 2020	Dec. 31, 2020
Non-recourse debt [Member] | Solar Renewable Energy Credit Loan Facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 45,389
Net Carrying Value, Current	17,025
Net Carrying Value, Long - Term	$ 28,509
Interest Rate	7.00%
Maturity Dates	Jul. 31, 2021
Non-recourse debt [Member] | Term Loan due in December 2018 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 154,573
Net Carrying Value, Current	3,943
Net Carrying Value, Long - Term	150,306
Unused Committed Amount	$ 21,299
Interest Rate	4.70%
Maturity Dates	Dec. 31, 2018
Non-recourse debt [Member] | Term Loan due in January 2021 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 178,820	$ 183,388
Net Carrying Value, Current	5,745	5,860
Net Carrying Value, Long - Term	$ 171,938	$ 176,169
Interest Rate	4.80%	4.50%
Maturity Dates	Jan. 31, 2021	Jan. 31, 2021
Non-recourse debt [Member] | Cash Equity Debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 488,000	$ 496,654
Net Carrying Value, Current	12,397	13,642
Net Carrying Value, Long - Term	$ 459,987	$ 466,741
Maturity Date, Start	Jul. 31, 2033	Jul. 31, 2033
Maturity Date, End	Jan. 31, 2035	Jan. 31, 2035
Non-recourse debt [Member] | Revolving Aggregation Credit Facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 420,265	$ 424,757
Net Carrying Value, Long - Term	417,681	427,944
Unused Committed Amount	$ 179,735	$ 335,243
Maturity Dates	Dec. 31, 2019	Dec. 31, 2018
Non-recourse debt [Member] | Solar Asset-backed notes [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 438,417	$ 458,836
Net Carrying Value, Current	16,403	16,113
Net Carrying Value, Long - Term	$ 406,327	$ 426,651
Maturity Date, Start	Nov. 30, 2038	Nov. 30, 2038
Maturity Date, End	Sep. 30, 2046	Sep. 30, 2046
Non-recourse debt [Member] | Solar Loan-backed Notes [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 244,498	$ 140,586
Net Carrying Value, Current	8,003	3,514
Net Carrying Value, Long - Term	$ 228,723	$ 133,510
Maturity Dates		Sep. 30, 2048
Maturity Date, Start	Sep. 30, 2048
Maturity Date, End	Sep. 30, 2049
Non-recourse debt [Member] | Asset Backed Notes Series Two Thousand Fourteen Two
Debt Instrument [Line Items]
Interest Rate		5.40%
Non-recourse debt [Member] | Asset Backed Notes Series Two Thousand Fifteen One
Debt Instrument [Line Items]
Interest Rate		5.60%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2016-1 [Member]
Debt Instrument [Line Items]
Interest Rate		7.50%
Non-recourse debt [Member] | Loan Backed Notes Series Two Thousand Sixteen A
Debt Instrument [Line Items]
Interest Rate		6.90%
Non-recourse debt [Member] | Term Loan due in December 2017 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance		$ 75,467
Net Carrying Value, Current		75,715
Unused Committed Amount		$ 52,173
Interest Rate		4.20%
Maturity Dates		Dec. 31, 2017
Non-recourse debt [Member] | My Power Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance		$ 133,762
Net Carrying Value, Current		133,827
Unused Committed Amount		$ 56,238
Maturity Dates		Jan. 31, 2017
Non-recourse debt [Member] | Solar Renewable Energy Credit Term Loan [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance		$ 38,124
Net Carrying Value, Current		12,491
Net Carrying Value, Long - Term		$ 26,262
Maturity Date, Start		Apr. 30, 2017
Maturity Date, End		Jul. 31, 2021
Non-recourse debt [Member] | Minimum [Member] | Canada Credit Facility [Member]
Debt Instrument [Line Items]
Interest Rate	3.60%	3.60%
Non-recourse debt [Member] | Minimum [Member] | Cash Equity Debt [Member]
Debt Instrument [Line Items]
Interest Rate	5.30%	5.30%
Non-recourse debt [Member] | Minimum [Member] | Revolving Aggregation Credit Facility [Member]
Debt Instrument [Line Items]
Interest Rate	4.10%	4.00%
Non-recourse debt [Member] | Minimum [Member] | Solar Asset-backed notes [Member]
Debt Instrument [Line Items]
Interest Rate	4.00%	4.00%
Non-recourse debt [Member] | Minimum [Member] | Solar Loan-backed Notes [Member]
Debt Instrument [Line Items]
Interest Rate	4.80%	4.80%
Non-recourse debt [Member] | Minimum [Member] | My Power Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest Rate		4.10%
Non-recourse debt [Member] | Minimum [Member] | Solar Renewable Energy Credit Term Loan [Member]
Debt Instrument [Line Items]
Interest Rate		6.60%
Non-recourse debt [Member] | Maximum [Member] | Canada Credit Facility [Member]
Debt Instrument [Line Items]
Interest Rate	4.50%	4.50%
Non-recourse debt [Member] | Maximum [Member] | Cash Equity Debt [Member]
Debt Instrument [Line Items]
Interest Rate	5.80%	5.80%
Non-recourse debt [Member] | Maximum [Member] | Revolving Aggregation Credit Facility [Member]
Debt Instrument [Line Items]
Interest Rate	4.80%	4.80%
Non-recourse debt [Member] | Maximum [Member] | Solar Asset-backed notes [Member]
Debt Instrument [Line Items]
Interest Rate	5.60%	7.50%
Non-recourse debt [Member] | Maximum [Member] | Solar Loan-backed Notes [Member]
Debt Instrument [Line Items]
Interest Rate	7.50%	6.90%
Non-recourse debt [Member] | Maximum [Member] | My Power Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest Rate		6.60%
Non-recourse debt [Member] | Maximum [Member] | Solar Renewable Energy Credit Term Loan [Member]
Debt Instrument [Line Items]
Interest Rate		9.90%
Secured Revolving Credit Facility [Member] | Recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance		$ 364,000
Net Carrying Value, Current		366,247
Unused Committed Amount		$ 24,305
Maturity Date, Start		Jan. 31, 2017
Maturity Date, End		Dec. 31, 2017
Secured Revolving Credit Facility [Member] | Recourse debt [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate		4.00%
Secured Revolving Credit Facility [Member] | Recourse debt [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate		6.00%