Valuation and Qualifying Accounts and Reserves (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 780	$ 735		$ 1,033
Additions (reductions) to Costs and Expenses	1,888	117		195
Write offs	(169)	(70)		(482)
Charged to Other Accounts	0	0		0
Reclassification from Other Accounts	(15)	(2)		(11)
Balance at End of Period	2,484	780		735
Allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	20,224	6,079		6,182
Additions (reductions) to Costs and Expenses	8,507	(680)		(103)
Write offs	(1,675)	0		0
Charged to Other Accounts		14,825	[1]	0
Reclassification from Other Accounts		0		0
Balance at End of Period	$ 27,056	$ 20,224		$ 6,079

[1] For the year ended December 31, 2011, we increased the valuation allowance in connection with acquired deferred tax assets and non-U.S. net operating losses, which resulted in a corresponding increase to goodwill, related to the Cadent acquisition.