Other Long-Term Financial Liabilities Impact of Failed Sale Leasebacks, Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Long-Term Financial Liabilities [Line Items]
Depreciation and amortization	$ 17,306	$ 16,975	$ 52,620	$ 51,120
Interest expense	$ 3,938	$ 4,816	12,587	$ 14,832
Failed Sale Leasebacks
Other Long-Term Financial Liabilities [Line Items]
Depreciation and amortization			438
Interest expense			$ 374