Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 65,290	$ 33,320	$ 24,651
Gross increases — tax positions of prior periods	6,391	11,238	12,925
Gross increases — current-period tax positions	6,252	27,043	2,106
Gross decreases — tax positions of prior periods	(6,778)	(5,996)	(6,362)
Gross decreases — settlements	(2,038)	(315)	0
Balance at end of year	$ 69,117	$ 65,290	$ 33,320