Schedule I - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended											12 Months Ended
	Dec. 31, 2015	Jan. 31, 2015	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	[2]	Mar. 31, 2015	Dec. 31, 2014		Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities:
Net income			$ (11,028)	[1]	$ 97,950	$ 5,809		$ (43,598)	$ (25,446)	[3]	$ 87,176	$ 37,406	$ (49,217)	$ 49,133	$ 49,919	$ 51,920
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities														286,274	261,532	286,461
Cash Flows From Investing Activities:
Net cash used in investing activities														(157,377)	(156,546)	(166,376)
Cash Flows From Financing Activities:
Proceeds from issuance of common stock, net of underwriter commissions																253,800
Purchase of treasury stock	$ (30,000)	$ (5,650)												(50,650)	(60,058)	(44,163)
Dividend paid to common stockholders														(72,318)	(72,113)	(36,175)
Offering costs																(4,694)
Net cash used in financing activities														(153,832)	(177,921)	(48,919)
Change in Cash and Cash Equivalents														(24,935)	(72,935)	71,166
Cash and Cash Equivalents—Beginning of period		43,906												43,906	116,841	45,675
Cash and Cash Equivalents—End of period	18,971		18,971						43,906					18,971	43,906	116,841
Supplemental Disclosures of Noncash Investing and Financing Activities
Dividends declared, but unpaid	430		430						172					430	172	17,939
Treasury stock purchases settled in January 2015		5,650							5,650						5,650
Parent Company [Member]
Cash Flows From Operating Activities:
Net income														49,133	49,919	51,920
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of subsidiary														(49,133)	(49,919)	(51,920)
Dividend received from subsidiary-return on capital (net of forfeitures)														36,196	36,056	18,072
Net cash provided by operating activities														36,196	36,056	18,072
Cash Flows From Investing Activities:
Capital contributed to subsidiary																(249,106)
Restricted payment from subsidiary														45,000	65,708	44,163
Dividend received from subsidiary-return of capital (net of forfeitures)														36,381	36,056	18,072
Net cash used in investing activities														81,381	101,764	(186,871)
Cash Flows From Financing Activities:
Proceeds from issuance of common stock, net of underwriter commissions																253,800
Purchase of treasury stock		(5,650)												(50,650)	(60,058)	(44,163)
Dividend paid to common stockholders														(72,318)	(72,113)	(36,175)
Offering costs																(4,694)
(Payment) receipt of cash for tax withholdings on equity-based compensation														(37)	37
Net cash used in financing activities														(123,005)	(132,134)	168,768
Change in Cash and Cash Equivalents														(5,428)	5,686	(31)
Cash and Cash Equivalents—Beginning of period		$ 5,858												5,858	172	203
Cash and Cash Equivalents—End of period	430		430						5,858					430	5,858	172
Supplemental Disclosures of Noncash Investing and Financing Activities
Dividends declared, but unpaid	$ 430		$ 430						172					$ 430	172	$ 17,939
Treasury stock purchases settled in January 2015									$ 5,650						$ 5,650

[1] During the fourth quarter of 2015, the Company recorded $2,001 in restructuring and other related costs primarily related to severance costs for certain positions which were eliminated as part of a cost savings initiative. See Note 4–Restructuring Program and Separation Costs for further details.

[2] During the second quarter of 2015, the Company recorded $20,348 in loss on early extinguishment of debt and write-off of discounts and debt issuance costs related to the early redemption of $260,000 of its Senior Notes. See Note 11–Long-Term Debt for further details.

[3] During the fourth quarter of 2014, the Company recorded $10,371 in restructuring and other related costs incurred in connection with the restructuring program which the Company implemented in December 2014. Also during the fourth quarter of 2014, the Company recorded $2,574 in separation costs representing costs incurred pursuant to the previously announced separation of the Company’s Former Chief Executive Officer and President on January 15, 2015. See Note 4–Restructuring Program and Separation Costs for further details.