Income Taxes - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 17,581	$ 47,190	$ 45,455
Additions based on tax positions related to the current year	1,969	3,303	3,238
Additions for tax positions of prior years	61	6,415	3,759
Reductions for tax positions for prior years	(3,152)	(851)	(1,472)
Reduction for lapse in statute of limitations	(425)	(481)	(1,714)
Settlements	(219)	(37,995)	(2,076)
Balance at end of year	$ 15,815	$ 17,581	$ 47,190