Amortization Expense of Other Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 6,093	$ 4,690	$ 18,282	$ 14,529