Net Carrying Amount of Debt (Detail) - USD ($) $ in Thousands		Dec. 31, 2020		Dec. 31, 2019
Debt Instrument [Line Items]
Total debt		$ 564,786
Unamortized debt issuance costs		(385)		$ (1,714)
Total debt	[1]	564,401		645,721
Less current maturities		28,433		61,976
Total long-term debt		535,968		583,745
Senior Secured Notes
Debt Instrument [Line Items]
Total debt		317,856		338,130
Less current maturities		8,400		42,700
Variable Funding Notes
Debt Instrument [Line Items]
Total debt		100,000		99,610
Senior Secured Term Loan
Debt Instrument [Line Items]
Total debt		94,755		162,418
Less current maturities		19,300		19,300
Convertible Notes | 5.75% Senior Subordinated Notes Due August 2023
Debt Instrument [Line Items]
Total debt	[3]	50,868	[2]	47,277
Total debt		94,400		$ 94,400
Payroll Protection Program Loan
Debt Instrument [Line Items]
Total debt	[4]	$ 1,307

[1] Carrying amounts include aggregate unamortized debt discount and debt issuance costs.

[2] Reflects the debt carrying amount which is accounted for under the Fair Value Option in the consolidated balance sheet as of December 31, 2020. The actual principal outstanding balance of the 5.75% Convertible Notes is $94.4 million as of December 31, 2020.

[3] Reflects the debt carrying amount, which is accounted for under the Fair Value Option in the consolidated balance sheet as of December 31, 2020 and December 31, 2019. The actual principal outstanding balance of the 5.75% Convertible Notes is $94.4 million and $94.4 million as of December 31, 2020 and December 31, 2019, respectively

[4] The Payroll Protection Program Loan and related accrued interest are eligible for forgiveness, in whole or in part based on the usage of the proceeds. The Company intends to submit an application for the loan to be forgiven in conformity with the loan’s terms. The Company believes it qualifies for such forgiveness. However, there is no assurance the Company will be successful in obtaining approval from the U.S. Small Business Administration.