Income Taxes - Components of Income before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
United States	$ 934,476	$ 1,004,919	$ 978,824
Foreign	139,864	118,762	138,915
Income before income taxes	$ 1,074,340	$ 1,123,681	$ 1,117,739	$ 1,044,304	$ 1,018,932