Long-Term Debt - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended			0 Months Ended	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 27, 2010	Dec. 31, 2012	Jun. 30, 2012
Debt Instrument [Line Items]
Net proceeds from the sale of notes			$ 375,000,000	$ 20,000,000
Principal amount repurchased	16,200,000
Gain (loss) on debt extinguishment	(400,000)	(246,000)	(29,675,000)	(3,743,000)
Interest expense related to amortization of the bond discount			300,000
8.75% Senior Secured First Lien Notes
Debt Instrument [Line Items]
Interest rate of notes			8.75%		8.75%
Aggregate principal amount of Senior Secured First Lien Notes					400,000,000
Issuance price as percentage of principal amount					98.722%
Notes maturity date		Aug. 01, 2017
Date of first required payment		Feb. 01, 2011
Net proceeds from the sale of notes					388,000,000
Discount on bond					5,000,000
Fees for sale of notes					7,000,000
Redemption of Notes upon change in control, amount as percentage of principal amount including interest		101.00%
Redemption of Notes declaration of acceleration written percentage of principal amount		25.00%
8.75% Senior Secured First Lien Notes | Prior to August 1, 2013 Term One
Debt Instrument [Line Items]
Issuance price as percentage of principal amount		10.00%
Redemption price on principal amount with net proceeds, accrued and unpaid expense		103.00%
8.75% Senior Secured First Lien Notes | Prior to August 1, 2013, Term Two
Debt Instrument [Line Items]
Issuance price as percentage of principal amount		35.00%
Redemption price on principal amount with net proceeds, accrued and unpaid expense		108.75%
Rate on principal amount outstanding		65.00%
Redemption closing date		60 days
8.75% Senior Secured First Lien Notes | Prior to August 1, 2013, Term Three
Debt Instrument [Line Items]
Redemption price on principal amount with net proceeds, accrued and unpaid expense		100.00%
8.75% Senior Secured First Lien Notes | Twelve Months Beginning August 1, 2013, Term Four
Debt Instrument [Line Items]
Redemption price on principal amount with net proceeds, accrued and unpaid expense		106.563%
8.75% Senior Secured First Lien Notes | Twelve Months Beginning August 1, 2014, Term Four
Debt Instrument [Line Items]
Redemption price on principal amount with net proceeds, accrued and unpaid expense		104.375%
8.75% Senior Secured First Lien Notes | Twelve Months Beginning August 1, 2015, Term Four
Debt Instrument [Line Items]
Redemption price on principal amount with net proceeds, accrued and unpaid expense		102.188%
8.75% Senior Secured First Lien Notes | Twelve Months Beginning August 1, 2016, Term Four
Debt Instrument [Line Items]
Redemption price on principal amount with net proceeds, accrued and unpaid expense		100.00%
Notes Payable to Banks
Debt Instrument [Line Items]
Principal amount repurchased				40,000,000		40,000,000	20,000,000
Gain (loss) on debt extinguishment						$ (2,500,000)	$ (1,200,000)
Redemption price percentage of the principal amount for redeemed notes						103.00%	103.00%