Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Cash and cash equivalents	$ 870,494	$ 922,318
Current portion of restricted cash, including consolidated variable interest entities of $61,590 in June 30, 2016 and $46,321 in December 31, 2015	72,264	119,151
Prepaid expenses and other current assets, including consolidated variable interest entities of $100,411 in June 30, 2016 and $123,876 in December 31, 2015	117,841	139,335
Power plants, net, including consolidated variable interest entities of $461,067 in June 30, 2016 and $460,042 in December 31, 2015	1,375,254	1,206,604
Intangible assets, net, including consolidated variable interest entities of $51,362 in June 30, 2016 and $51,159 in December 31, 2015	70,054	70,630
Other assets	40,211	51,809
Current portion of long-term debt, including consolidated variable interest entities of $333,144 in June 30, 2016 and $326,535 in December 31, 2015	324,225	319,498
Accrued expenses and other current liabilities, including consolidated variable interest entities of $46,773 in June 30, 2016 and $15,496 in December 31, 2015	111,305	129,437
Other long-term liabilities	$ 8,044	$ 1,455
Common Class A
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,750,000,000	2,750,000,000
Common stock, shares issued	113,101,162	114,630,318
Common stock, shares outstanding	113,101,162	114,630,318
Common Class B
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	61,343,054	61,343,054
Common stock, shares outstanding	61,343,054	61,343,054
Common Class B1
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	550,000,000	550,000,000
Common stock, shares issued	0	0
Common stock, shares outstanding	0	0
Variable interest entities
Cash and cash equivalents
Current portion of restricted cash, including consolidated variable interest entities of $61,590 in June 30, 2016 and $46,321 in December 31, 2015	61,590	46,321
Prepaid expenses and other current assets, including consolidated variable interest entities of $100,411 in June 30, 2016 and $123,876 in December 31, 2015	100,411	123,876
Power plants, net, including consolidated variable interest entities of $461,067 in June 30, 2016 and $460,042 in December 31, 2015	461,067	460,042
Intangible assets, net, including consolidated variable interest entities of $51,362 in June 30, 2016 and $51,159 in December 31, 2015	51,362	51,159
Current portion of long-term debt, including consolidated variable interest entities of $333,144 in June 30, 2016 and $326,535 in December 31, 2015	333,144	326,535
Accrued expenses and other current liabilities, including consolidated variable interest entities of $46,773 in June 30, 2016 and $15,496 in December 31, 2015	46,773	15,496
Other long-term liabilities
Deferred tax liabilities, including consolidated variable interest entities of $26,714 in June 30, 2016 and $37,295 in December 31, 2015	$ 38,615	$ 37,295