11. Revenue from Contracts with Customers (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) Projects	Mar. 31, 2018 USD ($) Projects	Dec. 31, 2018 USD ($)
Revenue from Contracts with Customers [Line Items]
Net sales	$ 531,978	$ 567,265
Project Change in Estimate Disclosure Threshold	$ 1,000
Number of Projects with Changes in Estimates | Projects	8	23
Increase in Revenue from Net Changes in Transaction Prices	$ 6,114	$ 53,150
(Decrease) Increase in Revenue from Net Changes in Input Cost Estimates	(15,950)	1,955
Net (Decrease) Increase in Revenue from Net Changes in Estimates	$ (9,836)	$ 55,105
Net Change in Estimate as a Percentage of Aggregate Revenue	(0.50%)	0.50%
Increase in Revenue from Net Changes in Indirect Tax Estimates		$ 54,600
Accounts receivable, unbilled	$ 347,726		$ 441,666
Retainage	19,414		16,500
Accounts receivable, unbilled and retainage	367,140		458,166
Contract Asset, Net Change	$ (91,026)
Contract Asset, Percent Change	(20.00%)
Deferred Revenue	$ 217,435		177,769
Contract Liability, Net Change	$ 39,666
Contract Liability, Percent Change	22.00%
Deferred Revenue, Noncurrent	$ 50,451		$ 48,014
Sales Revenue Net, from Beginning Contract Liability	46,700	33,800
Solar Modules [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	198,815	161,293
Remaining Performance Obligation, Transaction Price	3,400,000
Solar Power Systems [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	157,294	354,410
EPC Services [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	137,594	12,718
O&M Services [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	27,700	26,714
Remaining Performance Obligation, Transaction Price	$ 600,000
Revenue, Remaining Performance Obligation, Period of Recognition	11 years 2 months
Energy Generation [Member]
Revenue from Contracts with Customers [Line Items]
Net sales	$ 10,575	$ 12,130
Solar Power Systems, Sales of and EPC Services [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligation, Transaction Price	$ 500,000
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	43.00%
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	16.00%
Solar Power Systems, Sales of and EPC Services [Member] | Rosamond [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligations, Percent of Revenue Recognized	97.00%
Solar Power Systems, Sales of and EPC Services [Member] | Beryl [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligations, Percent of Revenue Recognized	0.00%
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%
Solar Power Systems, Sales of and EPC Services [Member] | Lake Hancock [Member]
Revenue from Contracts with Customers [Line Items]
Remaining Performance Obligations, Percent of Revenue Recognized	97.00%