Indebtedness - Summary of Debt (Detail) - USD ($) $ in Thousands			12 Months Ended
	Sep. 30, 2014	Oct. 31, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 16, 2016	Sep. 08, 2016	May 02, 2016	Sep. 23, 2014
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 3,580,405	$ 2,753,746
Current, Carrying Value, Net of Fees			818,798	372,221
Long-Term, Carrying Value, Net of Fees			2,676,773	2,332,600
Unused Committed Amount			$ 467,959	234,235
2.75% convertible senior notes due in 2018 [Member]
Debt Instrument [Line Items]
Maturity Date		Nov. 01, 2018
Interest Rate		2.75%
1.625% convertible senior notes due in 2019 [Member]
Debt Instrument [Line Items]
Maturity Date	Nov. 01, 2019
Interest Rate								1.625%
Zero-Coupon Convertible Senior Notes Due in 2020 [Member]
Debt Instrument [Line Items]
Maturity Date			Dec. 01, 2020
Solar Bonds [Member]
Debt Instrument [Line Items]
Long-Term, Carrying Value, Net of Fees			$ 331,861	214,087
MyPower revolving credit facility [Member] | Class A [Member]
Debt Instrument [Line Items]
Interest Rate			2.50%
Cash Equity Debt - I [Member]
Debt Instrument [Line Items]
Interest Rate							5.65%
Cash Equity Debt - II [Member]
Debt Instrument [Line Items]
Interest Rate						5.25%
Cash Equity Debt - III [Member]
Debt Instrument [Line Items]
Interest Rate					5.81%
Recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 1,628,831	1,511,497
Current, Carrying Value, Net of Fees			559,774	213,191
Long-Term, Carrying Value, Net of Fees			1,041,678	1,279,235
Unused Committed Amount			24,305	13,053
Recourse debt [Member] | Secured revolving credit facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			364,000	360,000
Current, Carrying Value, Net of Fees			360,957	22,320
Long-Term, Carrying Value, Net of Fees				333,287
Unused Committed Amount			$ 24,305	$ 13,053
Maturity Date, Start			Jan. 31, 2017	Dec. 31, 2016
Maturity Date, End			Dec. 31, 2017	Dec. 31, 2017
Recourse debt [Member] | Secured revolving credit facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate			4.00%	3.50%
Recourse debt [Member] | Secured revolving credit facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate			6.00%	5.80%
Recourse debt [Member] | Vehicle and other loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 23,771	$ 28,173
Current, Carrying Value, Net of Fees			17,235	12,562
Long-Term, Carrying Value, Net of Fees			$ 6,536	$ 15,610
Maturity Date, Start			Mar. 31, 2017	Jan. 31, 2016
Maturity Date, End			Jun. 30, 2019	Jun. 30, 2019
Recourse debt [Member] | Vehicle and other loans [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate			2.90%	2.50%
Recourse debt [Member] | Vehicle and other loans [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate			7.60%	7.60%
Recourse debt [Member] | 2.75% convertible senior notes due in 2018 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 230,000	$ 230,000
Long-Term, Carrying Value, Net of Fees			$ 226,323	$ 225,795
Maturity Date			Nov. 30, 2018	Nov. 30, 2018
Interest Rate			2.80%	2.80%
Recourse debt [Member] | 1.625% convertible senior notes due in 2019 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 566,000	$ 566,000
Long-Term, Carrying Value, Net of Fees			$ 557,112	$ 555,981
Maturity Date			Nov. 30, 2019	Nov. 30, 2019
Interest Rate			1.60%	1.60%
Recourse debt [Member] | Zero-Coupon Convertible Senior Notes Due in 2020 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 113,000	$ 113,000
Long-Term, Carrying Value, Net of Fees			$ 101,428	$ 112,784
Maturity Date			Dec. 31, 2020	Dec. 31, 2020
Interest Rate			0.00%	0.00%
Recourse debt [Member] | Solar Bonds [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 332,060	$ 214,324
Current, Carrying Value, Net of Fees			181,582	178,309
Long-Term, Carrying Value, Net of Fees			$ 150,279	$ 35,778
Maturity Date, Start			Jan. 31, 2017	Jan. 31, 2016
Maturity Date, End			Jan. 31, 2031	Dec. 31, 2030
Recourse debt [Member] | Solar Bonds [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate			1.10%	1.30%
Recourse debt [Member] | Solar Bonds [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate			6.50%	5.80%
Non-recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 1,951,574	$ 1,242,249
Current, Carrying Value, Net of Fees			259,024	159,030
Long-Term, Carrying Value, Net of Fees			1,635,095	1,053,365
Unused Committed Amount			443,654	221,182
Non-recourse debt [Member] | Term loan due in December 2017 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			75,467
Current, Carrying Value, Net of Fees			73,825
Unused Committed Amount			$ 52,173
Maturity Date			Dec. 31, 2017
Interest Rate			4.20%
Non-recourse debt [Member] | Term loan due in January 2021 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 183,388
Current, Carrying Value, Net of Fees			5,860
Long-Term, Carrying Value, Net of Fees			$ 171,994
Maturity Date			Jan. 31, 2021
Interest Rate			4.50%
Non-recourse debt [Member] | MyPower revolving credit facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 133,762	213,125
Current, Carrying Value, Net of Fees			133,578
Long-Term, Carrying Value, Net of Fees				210,735
Unused Committed Amount			$ 56,238	$ 26,875
Maturity Date			Jan. 31, 2017	Jan. 31, 2017
Non-recourse debt [Member] | MyPower revolving credit facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate			4.10%	3.00%
Non-recourse debt [Member] | MyPower revolving credit facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate			6.60%	5.50%
Non-recourse debt [Member] | Revolving aggregation credit facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 424,757	$ 455,693
Long-Term, Carrying Value, Net of Fees			413,792	446,963
Unused Committed Amount			$ 335,243	$ 194,307
Maturity Date			Dec. 31, 2018	Dec. 31, 2017
Non-recourse debt [Member] | Revolving aggregation credit facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate			4.00%	3.10%
Non-recourse debt [Member] | Revolving aggregation credit facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate			4.80%	3.20%
Non-recourse debt [Member] | Solar Renewable Energy Credit Term Loan [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 38,124
Current, Carrying Value, Net of Fees			12,491
Long-Term, Carrying Value, Net of Fees			$ 24,565
Maturity Date, Start			Apr. 30, 2017
Maturity Date, End			Jul. 31, 2021
Non-recourse debt [Member] | Solar Renewable Energy Credit Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate			6.60%
Non-recourse debt [Member] | Solar Renewable Energy Credit Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate			9.90%
Non-recourse debt [Member] | Cash Equity Debt - I [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 119,753
Current, Carrying Value, Net of Fees			3,272
Long-Term, Carrying Value, Net of Fees			$ 115,464
Maturity Date			Jul. 31, 2033
Interest Rate			5.70%
Non-recourse debt [Member] | Cash Equity Debt - II [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 206,901
Current, Carrying Value, Net of Fees			5,376
Long-Term, Carrying Value, Net of Fees			$ 198,220
Maturity Date			Jul. 31, 2034
Interest Rate			5.30%
Non-recourse debt [Member] | Cash Equity Debt - III [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 170,000
Current, Carrying Value, Net of Fees			4,994
Long-Term, Carrying Value, Net of Fees			$ 161,855
Maturity Date			Jan. 31, 2035
Interest Rate			5.80%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2013-1 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 41,899	$ 45,845
Current, Carrying Value, Net of Fees			3,330	3,342
Long-Term, Carrying Value, Net of Fees			$ 35,826	$ 39,669
Maturity Date			Nov. 30, 2038	Nov. 30, 2038
Interest Rate			4.80%	4.80%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-1 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 60,768	$ 64,431
Current, Carrying Value, Net of Fees			3,016	2,855
Long-Term, Carrying Value, Net of Fees			$ 55,197	$ 58,938
Maturity Date			Apr. 30, 2044	Apr. 30, 2044
Interest Rate			4.60%	4.60%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-2 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 186,851	$ 193,755
Current, Carrying Value, Net of Fees			7,055	6,319
Long-Term, Carrying Value, Net of Fees			$ 173,625	$ 181,041
Maturity Date			Jul. 31, 2044	Jul. 31, 2044
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-2 [Member] | Class A [Member]
Debt Instrument [Line Items]
Interest Rate			4.00%	4.00%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-2 [Member] | Class B [Member]
Debt Instrument [Line Items]
Interest Rate			5.40%	5.40%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2015-1 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 119,199	$ 122,295
Current, Carrying Value, Net of Fees			1,511	1,348
Long-Term, Carrying Value, Net of Fees			$ 112,927	$ 116,019
Maturity Date			Aug. 31, 2045	Aug. 31, 2045
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2015-1 [Member] | Class A [Member]
Debt Instrument [Line Items]
Interest Rate			4.20%	4.20%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2015-1 [Member] | Class B [Member]
Debt Instrument [Line Items]
Interest Rate			5.60%	5.60%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2016-1 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 50,119
Current, Carrying Value, Net of Fees			1,202
Long-Term, Carrying Value, Net of Fees			$ 44,313
Maturity Date			Sep. 30, 2046
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2016-1 [Member] | Class A [Member]
Debt Instrument [Line Items]
Interest Rate			5.30%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2016-1 [Member] | Class B [Member]
Debt Instrument [Line Items]
Interest Rate			7.50%
Non-recourse debt [Member] | Solar Loan-backed Notes, Series 2016-A [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$ 140,586
Current, Carrying Value, Net of Fees			3,514
Long-Term, Carrying Value, Net of Fees			$ 127,317
Maturity Date			Sep. 30, 2048
Non-recourse debt [Member] | Solar Loan-backed Notes, Series 2016-A [Member] | Class A [Member]
Debt Instrument [Line Items]
Interest Rate			4.80%
Non-recourse debt [Member] | Solar Loan-backed Notes, Series 2016-A [Member] | Class B [Member]
Debt Instrument [Line Items]
Interest Rate			6.90%
Non-recourse debt [Member] | Term loan due in May 2016 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value				$ 34,622
Current, Carrying Value, Net of Fees				$ 33,918
Maturity Date				May 31, 2016
Interest Rate				3.50%
Non-recourse debt [Member] | Term loan due in December 2016 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value				$ 112,483
Current, Carrying Value, Net of Fees				$ 111,248
Maturity Date				Dec. 31, 2016
Non-recourse debt [Member] | Term loan due in December 2016 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest Rate				3.60%
Non-recourse debt [Member] | Term loan due in December 2016 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest Rate				3.70%