Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits, Beginning Balance	$ 57,125	$ 47,146	$ 32,419
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	436	0	10,216
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	1,868	9,979	11,006
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	0	0	6,495
Unrecognized Tax Benefits, Ending Balance	$ 59,429	$ 57,125	$ 47,146