Stockholders' Equity and Share-based Compensation - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended				12 Months Ended
	Aug. 31, 2011	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized total share-based compensation costs						$ 9,214,000	$ 8,118,000	$ 7,490,000
Number of Restricted Stock Units, Granted						32,834
Vested stock appreciation rights, outstanding, intrinsic value		2,700,000				2,700,000	100,000
Aggregate intrinsic value of common stock options, outstanding		1,200,000				1,200,000	700,000
Authorization of common stock repurchase	50,000,000					10,007,000	40,307,000	0
Number of shares repurchased						200,000	1,300,000
Cost of shares repurchased						10,000,000	40,300,000
Remaining share repurchase authorization							18,100,000
Cash dividend declared per share		$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.70	$ 0.60	$ 0.44
Preferred stock, shares authorized		5,000,000				5,000,000	5,000,000
Preferred stock, par value		$ 0.01				$ 0.01	$ 0.01
Preferred stock, shares issued		0				0	0
Preferred stock, shares outstanding		0				0	0
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional authorization of common stock repurchase						50,000,000
Cash dividend declared per share						$ 0.225
Share-based Compensation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares contractual term						4 years
Expected forfeiture rate						14.00%	14.00%	14.00%
Share-based compensation arrangements, income tax benefit						3,700,000	3,200,000	3,000,000
Total unrecognized share-based compensation cost which is expected to be recognized		21,300,000				21,300,000
Total compensation cost not yet recognized, period for recognition						2 years
Common stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of common stock options, exercised						400,000	500,000	100,000
Common stock options [Member] | Range One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Shares		80,905				80,905	124,750
2004 and 2012 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock under stock incentive plan		5,600,000				5,600,000
Issuance if common stock under prior equity compensation plans		11,198,113				11,198,113
2004 and 2012 Stock Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of equity awards						4 years
2004 and 2012 Stock Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of equity awards						7 years
2012 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock under stock incentive plan		7,500,000				7,500,000
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of equity awards								4 years 9 months 18 days
Intrinsic value of SAR's						387,880	15,000
Aggregate intrinsic value of common stock options, exercised						$ 500,000	$ 100,000