Nature of Business, Basis of Presentation and Summary of Significant Accounting Policies (Supplemental Cash Flow Information) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplemental disclosures of cash flow information:
Interest paid	$ 62,513	$ 76,846
Income taxes paid	5,775	18,590
Supplemental disclosures of non-cash flow information:
Trade revenue	34,203	45,308
Trade expense	33,604	44,378
Non-cash principal increase in financing liabilities	638	776
Reconciliation of cash and cash equivalents and restricted cash to the Consolidated Balance Sheet:
Cash and cash equivalents	271,761	15,142
Restricted cash	0	1,865
Total cash and cash equivalents and restricted cash	$ 271,761	$ 17,007	$ 30,038