Intangible Assets and Goodwill (Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Finite lived intangible assets
Gross Carrying Amount	$ 287,199		$ 287,199
Accumulated Amortization	(134,934)		(127,360)
Net Carrying Amount	152,265		159,839
Amortization expense	8,000	$ 9,000
Customer relationships
Finite lived intangible assets
Gross Carrying Amount	268,199		268,199
Accumulated Amortization	(121,634)		(115,010)
Net Carrying Amount	146,565		153,189
Software & technology
Finite lived intangible assets
Gross Carrying Amount	19,000		19,000
Accumulated Amortization	(13,300)		(12,350)
Net Carrying Amount	$ 5,700		$ 6,650