Cash and Cash Equivalent Balances (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents in domestic accounts	$ 392,133	$ 225,396
Cash and cash equivalents in foreign accounts	55,717	63,787
Total	$ 447,850	$ 289,183	$ 266,041