Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 33,320	$ 24,651	$ 20,902
Gross increases — tax positions of prior periods	11,238	12,925	2,878
Gross increases — current-period tax positions	27,043	2,106	2,834
Gross decreases — tax positions of prior periods	(5,996)	(6,362)	(1,213)
Gross decreases — settlements	(315)	0	(750)
Balance at end of year	$ 65,290	$ 33,320	$ 24,651