Schedule I - Condensed Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended											12 Months Ended
	Dec. 31, 2015	[1]	Sep. 30, 2015	Jun. 30, 2015	[2]	Mar. 31, 2015	Dec. 31, 2014	[3]	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net income	$ (11,028)		$ 97,950	$ 5,809		$ (43,598)	$ (25,446)		$ 87,176	$ 37,406	$ (49,217)	$ 49,133	$ 49,919	$ 51,920
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Equity in net income of subsidiary												49,133	49,919	51,920
Net income												49,133	49,919	51,920
Comprehensive income												$ 49,133	$ 49,919	$ 51,920

[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.