7. Restricted Cash and Investments (Details) - Restricted Cash and Restricted Investments - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Restricted cash	$ 43,851		$ 31,381
Restricted investments	365,022		339,926
Restricted cash and investments, noncurrent	408,873		371,307
Restricted cash, current	$ 16,552		37,154
Solar module collection and recycling custodial account	90 days
Product minimum service life	25 years
Restricted Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	$ 365,022		$ 339,926
Proceeds from sale of restricted investments		$ 106,100
Restricted investments, gross realized gains		$ 37,800