11. Revenue from Contracts with Customers (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) Projects	Jun. 30, 2018 USD ($) Projects	Jun. 30, 2019 USD ($) Projects	Jun. 30, 2018 USD ($) Projects	Dec. 31, 2018 USD ($)
Revenue from Contracts with Customers [Line Items]
Net sales	$ 584,956	$ 309,318	$ 1,116,934	$ 876,583
Project Change in Estimate Disclosure Threshold			$ 1,000
Number of Projects with Changes in Estimates | Projects	3	1	5	23
(Decrease) increase in Revenue from Net Changes in Transaction Prices	$ (4,064)	$ (4,513)	$ 4,697	$ 48,277
Decrease in Revenue from Net Changes in Input Cost Estimates	(1,749)	(12,160)	(16,736)	(10,281)
Net (Decrease) Increase in Revenue from Net Changes in Estimates	$ (5,813)	$ (16,673)	$ (12,039)	$ 37,996
Net Change in Estimate as a Percentage of Aggregate Revenue	(0.40%)	(1.90%)	(0.70%)	0.40%
Increase in Revenue from Net Changes in Indirect Tax Estimates				$ 54,600
Accounts receivable, unbilled	$ 103,171		$ 103,171		$ 441,666
Retainage	24,801		24,801		16,500
Accounts receivable, unbilled and retainage	127,972		127,972		458,166
Contract Asset, Net Change			$ (330,194)
Contract Asset, Percent Change			(72.00%)
Deferred Revenue	157,682		$ 157,682		177,769
Contract Liability, Net Change			$ (20,087)
Contract Liability, Percent Change			(11.00%)
Deferred Revenue, Noncurrent	45,445		$ 45,445		$ 48,014
Sales Revenue Net, from Beginning Contract Liability			69,800	55,000
Solar Modules [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	228,745	$ 105,332	427,560	266,625
Remaining Performance Obligation, Transaction Price	3,500,000		3,500,000
Solar Power Systems [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	217,755	109,659	375,049	464,069
EPC Services [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	102,457	56,854	240,051	69,572
O&M Services [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	26,452	24,427	54,152	51,141
Remaining Performance Obligation, Transaction Price	$ 600,000		$ 600,000
Revenue, Remaining Performance Obligation, Period of Recognition	11 years		11 years
Energy Generation [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	$ 9,547	$ 13,046	$ 20,122	$ 25,176
Solar Power Systems, Sales of and EPC Services [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligation, Transaction Price	$ 300,000		$ 300,000
Solar Power Systems, Sales of and EPC Services [Member] | Phoebe [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligations, Percent of Revenue Recognized	81.00%		81.00%
Solar Power Systems, Sales of and EPC Services [Member] | GA Solar 4 [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligations, Percent of Revenue Recognized	28.00%		28.00%
Solar Power Systems, Sales of and EPC Services [Member] | Troy Solar [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligations, Percent of Revenue Recognized	0.00%		0.00%