Accounts Payable and Accrued Liabilities (Schedule of Accounts Payable and Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued payroll and benefits	$ 12,920	$ 20,130
Accounts payable	12,734	12,073
Accrued interest	6,946	8,642
Accrued taxes	6,638	7,389
Deferred revenue	5,514	4,282
Operating lease liabilities	4,998
Other current liabilities	10,827	8,477
Total accounts payable and accrued liabilities	$ 60,577	$ 60,993