Quarterly Results (Unaudited) - Schedule of Quarterly Income Statement Including Basic and Diluted Earning Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Total revenues from continuing operations	$ 171,848	$ 164,179	$ 169,525	$ 129,283	$ 145,399	$ 125,488	$ 134,241	$ 128,785	$ 634,835	$ 533,913	$ 472,028
Operating income from continuing operations	19,225	13,503	23,409	3,417	16,723	7,235	15,932	14,450	59,554	54,340	35,025
Net income (loss)	$ 3,850	$ 1,009	$ 6,677	$ (5,783)	$ 91,645	$ 233	$ 1,198	$ 3,232	$ 5,753	$ 96,308	$ (7,710)
Net (loss) income per common share:
Basic	$ 0.17	$ 0.05	$ 0.38	$ (0.33)	$ 5.31	$ 0.01	$ 0.07	$ 0.25	$ 0.29	$ 6.11	$ (0.60)
Diluted	$ 0.16	$ 0.05	$ 0.37	$ (0.33)	$ 5.20	$ 0.01	$ 0.07	$ 0.25	$ 0.29	$ 5.99	$ (0.60)