Equity-Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended				1 Months Ended	12 Months Ended	1 Months Ended			12 Months Ended	1 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Time Based Restricted Stock	Dec. 31, 2012 Performance Based Restricted Stock	Dec. 31, 2012 Equity Incentive Plan	Apr. 25, 2012 Equity Incentive Plan Time Based Restricted Stock	Dec. 31, 2012 Equity Incentive Plan Time Based Restricted Stock	Apr. 25, 2012 Equity Incentive Plan Time Based Restricted Stock Executive officers	Apr. 25, 2012 Equity Incentive Plan Performance Based Restricted Stock	Apr. 25, 2012 Equity Incentive Plan Performance Based Restricted Stock Executive officers	Dec. 31, 2012 Equity Incentive Plan Stock Options	Jun. 07, 2012 Equity Incentive Plan Director	Feb. 11, 2011 Equity Incentive Plan Director	Dec. 31, 2012 2011 Equity Incentive Plan	Dec. 31, 2012 2011 Equity Incentive Plan Stock Options Minimum	Dec. 31, 2012 2011 Equity Incentive Plan Stock Options Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares provides for grants													2,318,290
Term of option														5 years	10 years
Options granted				940,000							15,288	4,000
Exercise price of options granted				$ 9.75
Vesting period					3 years			3 years		5 years
Restricted shares awarded		110,137	82,602				110,137		82,602
Vesting percentage						25.00%
Vesting percentage						25.00%
Vesting percentage						50.00%
Unrecognized compensation costs related to non-vested awards	$ 3.1
Share based compensation non-vested awards period of recognition	2 years