Debt - Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total long-term debt	$ 300,165	$ 298,177
Current portion of long-term debt	(37,192)	(36,553)
Long-term debt, less current portion	262,973	261,624
7.875% Senior Notes [Member]
Debt Instrument [Line Items]
Total long-term debt	250,000	250,000
6.50% Convertible Senior Notes, Net of Unamortized Discounts [Member]
Debt Instrument [Line Items]
Total long-term debt	34,914	34,417
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	3,977	2,596
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Total long-term debt	5,994	6,433
Other Long-term Notes Payable [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 5,280	$ 4,731