Borrowing Arrangements - Summary of Recognized Interest Expense on 2010 Notes and 2006 Notes (Detail) (Convertible Senior Subordinated Notes [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Convertible Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Contractual coupon interest	$ 1,590	$ 1,590
Amortization of discount	736	684
Amortization of deferred financing costs	180	180
Total interest expense	$ 2,506	$ 2,454