Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 200,206	$ 192,650
Accumulated Amortization	(88,398)	(73,270)
Indefinite-Lived Intangible Assets Not Subject to Amortization	29	29
Total intangible assets	200,235	192,679
Licenses
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets Not Subject to Amortization	29	29
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	41,693	41,809
Accumulated Amortization	(38,104)	(34,754)
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,450	1,393
Accumulated Amortization	(1,529)	(1,388)
Contracts / agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	155,063	147,090
Accumulated Amortization	(48,765)	(36,930)
Favorable lease contract
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0	2,358
Accumulated Amortization	$ 0	$ (198)