Net Carrying Amount of Debt (Detail) - USD ($) $ in Thousands		Dec. 31, 2019		Dec. 31, 2018
Debt Instrument [Line Items]
Total debt		$ 647,435
Unamortized debt issuance costs		(1,714)		$ (4,738)
Total debt	[1]	645,721		675,229
Less current maturities		61,976		54,263
Total long-term debt		583,745		620,966
Senior Secured Notes
Debt Instrument [Line Items]
Total debt		338,130		365,481
Less current maturities		42,700		42,700
Variable Funding Notes
Debt Instrument [Line Items]
Total debt		99,610	[2]	95,273
Senior Secured Term Loan
Debt Instrument [Line Items]
Total debt		162,418		171,137
Less current maturities		19,300		11,600
Convertible Notes | 5.75% Senior Subordinated Notes Due August 2023
Debt Instrument [Line Items]
Total debt		47,277	[3]	$ 48,076
Total debt		$ 94,400

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

[2] Reflects the net debt carrying amount, effected by the outstanding balance of the original issue discount, in the consolidated balance sheet as of December 31, 2019. The actual principal outstanding balance of the Variable Funding Notes is $100.0 million as of December 31, 2019

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