Equity Compensation Plans (Additional Information) (Detail) (USD $)	12 Months Ended					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Stock Option Plan 2012	Apr. 30, 2012 Stock Option Plan 2012	Dec. 31, 2013 Performance Based Restricted Stock Awards	Dec. 31, 2012 Performance Based Restricted Stock Awards	Dec. 31, 2011 Performance Based Restricted Stock Awards	Dec. 31, 2013 Restricted Stock	Dec. 31, 2012 Restricted Stock	Dec. 31, 2011 Restricted Stock	Dec. 31, 2013 Time Based Restricted Stock [Member]	Dec. 31, 2012 Time Based Restricted Stock [Member]	Dec. 31, 2013 Stock Options	Dec. 31, 2012 Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options and restricted shares authorized				1,750,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	1,200,000
Stock based compensation expense	$ 1,800,000	$ 1,400,000	$ 1,300,000
Cash received from exercise of stock option	1,500,000	1,000,000	100,000
Total intrinsic value for options exercised	1,000,000	700,000	100,000
Number of options granted	75,000	146,500	177,500
Total unrecognized compensation cost									1,600,000
Weighted average expected amortization period	2 years 10 months 24 days								2 years 1 month 6 days
Restricted shares Granted	124,000					95,090	114,500	22,000				29,480	73,750
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 9.41	$ 7.79	$ 5.43						$ 16.01	$ 12.56	$ 5.54
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period									10,565	171,369	59,440
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options	1,600,000
Stock Repurchased During Period, Shares				423,244
Stock Repurchased During Period, Value	6,617,000	3,998,000	200,000	6,100,000
Share Price				$ 14.30
Stock Repurchase Program, Number of Shares Authorized to be Repurchased				267,089	1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	1,600,000	600,000	600,000
Shares Exercised	(158,000)	129,675	35,874
Realized Income Tax Benefit	$ 1,000,000	$ 500,000	$ 400,000											$ 300,000	$ 200,000