Lease Obligations - Schedule of Lease Costs including Weighted Average Lease Terms and Weighted-average Discount Rates (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finance cost:
Interest on lease liability (included in Interest expense, net)	$ 1,635	$ 1,642
Short-term lease cost		44
Variable lease cost	244	309
Sublease income (included in Rentals, net)	(26,539)	(27,400)
Total lease cost	$ (21,131)	$ (21,885)
Operating lease, weighted average remaining lease term (in years)	40 years 8 months 12 days	41 years 6 months
Financelease, weighted average remaining lease term (in years)	3 years	4 years
Operating lease, weighted average discount rate, percent	4.90%	4.90%
Finance lease, weighted average discount rate, percent	7.50%	7.50%
Operating expense [Member]
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 2,977	$ 3,044
General and administrative expense [Member]
Lessee, Lease, Description [Line Items]
Operating lease cost	370	302
Depreciation and Amortization [Member]
Finance cost:
Amortization of right-of-use asset (included in Depreciation and Amortization)	$ 182	$ 174