Accrued Liabilities Long-term liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued Liabilities [Abstract]
Operating Lease, Liability, Noncurrent	$ 35,478	$ 41,019
Accrued Employee Benefits	1,109	1,183
Accrued Rent	1,312	1,462
Liabilities for contracts	236	337
Finance Lease, Liability, Noncurrent	2,122	2,388
Other Accrued Liabilities, Noncurrent	596	1,446
OTHER LONG-TERM LIABILITIES	$ 40,853	$ 47,835