Accounts Payable and Accrued Liabilities (Schedule of Accounts Payable and Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued payroll and benefits	$ 20,130	$ 18,110
Accounts payable	12,073	9,361
Accrued interest	8,642	6,385
Avery Landing accrual		6,000
Accrued taxes	7,389	5,103
Other current liabilities	12,759	10,242
Total accounts payable and accrued liabilities	$ 60,993	$ 55,201