Equity Based Compensation - Summary of Compensation Expense Charged Against Pretax Loss Under Restricted Stock Award (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit
Restricted stock and stock option awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	240	260	852	560
Restricted stock and stock option awards [Member] | 2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	47	71	279	290
Restricted stock and stock option awards [Member] | 2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 193	$ 189	$ 573	$ 270