Quarterly Financial Information (Unaudited) - Quarterly Financial Data (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]
Revenues	$ 266,070	$ 221,196	$ 245,183	$ 222,113	$ 266,321	$ 228,129	$ 253,229	$ 238,915	$ 954,562	$ 986,594	$ 952,144
Depreciation and amortization	27,549	27,916	29,054	32,009	37,302	30,701	30,254	32,434	116,528	130,691	125,289
Operating income (loss)	29,726	19,803	28,903	(2,244)	(24,597)	(33,449)	31,608	21,684	76,188	(4,754)	79,531
Income (loss) before income taxes and discontinued operations	17,970	5,783	14,584	(12,522)	(16,179)	(43,253)	20,287	10,476	25,815	(28,669)	17,488
(Provision) benefit for income taxes	12,136	12,450	1,784	66,292	1,236	16,581	(11,314)	(4,469)	92,662	2,034	(7,420)
Income (loss) from continuing operations	30,106	18,233	16,368	53,770	(14,943)	(26,672)	8,973	6,007	118,477	(26,635)	10,068
Income (loss) from discontinued operations, net of taxes	56	(202)	11	10	(9)	(2)	(19)	21	(125)	(9)	109
Net income (loss)	30,162	18,031	16,379	53,780	(14,952)	(26,674)	8,954	6,028	118,352	(26,644)	10,177
Net income (loss) available to common stockholders	$ 30,162	$ 18,031	$ 11,510	$ 53,780	$ (14,952)	$ (26,674)	$ 8,954	$ 6,028	$ 113,483	$ (26,644)	$ 10,177
Net income (loss) per share	$ 0.60	$ 0.36	$ 0.22	$ 1.03	$ (0.32)	$ (0.57)	$ 0.18	$ 0.12	$ 2.22	$ (0.56)	$ 0.21
Net income (loss) per share - assuming dilution	$ 0.48	$ 0.30	$ 0.18	$ 0.81	$ (0.32)	$ (0.57)	$ 0.17	$ 0.12	$ 1.81	$ (0.56)	$ 0.20