Fair Value of Financial Instruments - Estimated Fair Value of the Embedded Derivative (Detail) (Senior Subordinated Notes, USD $)	9 Months Ended		9 Months Ended
	Sep. 30, 2014 2018 Notes	Dec. 31, 2013 2018 Notes	Sep. 30, 2014 2019 Notes	Apr. 01, 2014 2019 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated fair value of the embedded derivative	$ 815,000	$ 5,914,000	$ 845,000	$ 3,903,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)	5,100,000		3,100,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	4,100,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3	$ 1,000,000