Changes In Stockholders' Equity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Stockholders' Equity [Line Items]
Balance as of December 31, 2011			$ 126,816
Net income	9,963	7,584	27,770	23,831
Common stock issued from treasury stock			3,164
Common stock repurchased			(50,025)
Common stock repurchased, Shares Outstanding			(1,372,853)
Excess tax benefits from share-based awards			554
Non-cash share-based compensation			4,377
Dividends declared			(5,337)
Other comprehensive income	(346)	213	369	463
Balance as of June 30, 2012	107,688		107,688
Common Stock
Stockholders' Equity [Line Items]
Balance as of December 31, 2011			16,169
Balance as of December 31, 2011, Shares Outstanding			27,290,000
Common stock issued from treasury stock, Shares Outstanding			195,000
Common stock repurchased, Shares Outstanding			(1,373,000)
Balance as of June 30, 2012	16,169		16,169
Balance as of June 30, 2012, Shares Outstanding	26,112,000		26,112,000
Treasury Stock
Stockholders' Equity [Line Items]
Balance as of December 31, 2011			(2,524)
Common stock issued from treasury stock			97
Common stock repurchased			(686)
Balance as of June 30, 2012	(3,113)		(3,113)
Retained Earnings
Stockholders' Equity [Line Items]
Balance as of December 31, 2011			128,772
Net income			27,770
Common stock issued from treasury stock			3,067
Common stock repurchased			(49,339)
Excess tax benefits from share-based awards			554
Non-cash share-based compensation			4,377
Dividends declared			(5,337)
Balance as of June 30, 2012	109,864		109,864
Accumulated Other Comprehensive Loss
Stockholders' Equity [Line Items]
Balance as of December 31, 2011			(15,601)
Other comprehensive income			369
Balance as of June 30, 2012	$ (15,232)		$ (15,232)