Stock-Based Compensation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Management Incentive Plan And Omnibus Incentive Plan [Member]	Sep. 30, 2012 Management Incentive Plan And Omnibus Incentive Plan [Member]	Sep. 30, 2013 Management Incentive Plan And Omnibus Incentive Plan [Member]	Sep. 30, 2012 Management Incentive Plan And Omnibus Incentive Plan [Member]
Preferred Stock [Line Items]
Total compensation expense recognized			$ 3,026	$ 3,436	$ 8,660	$ 11,473
Preferred stock dividend rate, percentage	7.00%	7.00%