Income Taxes - Summary of Liabilities Related to Reserve for Uncertain Tax Positions (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Reserve for uncertain tax positions, excluding interest and penalties	$ 107,748	$ 113,931	$ 105,028
Interest and penalties included in "Other liabilities"	8,039	13,190
Reserve for uncertain tax positions, including interest and penalties	$ 115,787	$ 127,121