Schedule 2 - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts Receivable [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 9,111	$ 6,673	$ 6,184
Additions Charged to cost and expenses	937	4,590	2,027
Additions Charged (credited) to other accounts			(13)
Deductions/ Other	(2,763)	(2,152)	(1,525)
Balance at end of year	7,285	9,111	6,673
Deferred Tax Valuation Allowance [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	31,772	26,361	19,124
Additions Charged to cost and expenses	5,666	5,411	7,237
Balance at end of year	$ 37,438	$ 31,772	$ 26,361