Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 21,426	$ 12,602	$ 65,672	$ 57,773
Effective income tax rate	41.40%	27.10%	37.40%	31.70%
Unrecognized tax benefits	$ 22,800		$ 22,800		$ 20,600
Unrecognized tax benefits reductions resulting from settlements with taxing authorities and lapse of applicable statute of limitations	1,400		$ 1,400
Gain on sale of tax credit	$ 5,400