Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental disclosures:
Cash paid for income taxes, net of refunds (received, net of payments)	$ 40	$ 26	$ (195)
Cash paid for interest	60,057	60,168	60,081
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	4,019
Operating cash flows from finance leases	20
Financing cash flows from finance leases	321
Non-cash investing and financing activities:
Change in capital expenditures included in accounts payable	$ 1,618	$ (1,031)	$ (2,982)