Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 955	$ 1,213	$ 1,166
Charged to Costs and Expenses	1,469	4,174	2,043
Charged to Other Accounts	(270)	(373)	(1,098)
Deductions from Reserves	(763)	(4,059)	(898)
Balance at end of year	1,391	955	1,213
Allowance for Deferred Income Tax Assets
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	13,418	18,037	2,199
Charged to Costs and Expenses	5,706
Charged to Other Accounts	180	(2,436)	16,674
Deductions from Reserves		(2,183)	(836)
Balance at end of year	19,304	13,418	18,037
Reserve for Inventory
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	4,308	4,802	2,933
Charged to Costs and Expenses	876	815	2,204
Charged to Other Accounts	(68)	(249)	(181)
Deductions from Reserves	(326)	(1,060)	(154)
Balance at end of year	$ 4,790	$ 4,308	$ 4,802