Cash and Cash Equivalent Balances (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents in domestic accounts	$ 405,248	$ 307,578
Cash and cash equivalents in foreign accounts	60,071	81,750
Cash and cash equivalents	$ 465,319	$ 389,328