Share Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 2005 Omnibus Stock Plan	Sep. 30, 2013 Stock Options and Restricted Stock Units	Sep. 30, 2012 Stock Options and Restricted Stock Units	Sep. 30, 2013 Stock Options and Restricted Stock Units	Sep. 30, 2012 Stock Options and Restricted Stock Units	Mar. 31, 2013 Stock Option	Sep. 30, 2013 Stock Option	Mar. 31, 2013 Restricted Stock	Sep. 30, 2013 Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorizes					1,800,000
Common stock, shares available for issuance					998,375
Exercise period, maximum			5 years 4 months 2 days	5 years 4 months 6 days	10 years
Minimum grant price percentage					100.00%
Stock options exercised			10,964	1,217
Recognized Compensation expense						$ 0.4	$ 0.4	$ 1.2	$ 1.0
Unrecognized Compensation expense											0.3		3.6
Expected cost recognition weighted average period											1 year 8 months 12 days		3 years 1 month 6 days
Fair value of shares vested	$ 0.2	$ 0.2
Stock granted			20,229							20,229		93,770
Vesting period										3 years		5 years