Acquisitions, Divestiture, Intangible Assets and Goodwill (Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite lived intangible assets
Gross Carrying Amount	$ 741,795	$ 631,288
Accumulated Amortization	(469,609)	(466,116)
Net Carrying Amount	272,186	165,172
Amortization period	34,000	38,000	$ 37,000
Customer relationships
Finite lived intangible assets
Gross Carrying Amount	526,149	445,039
Accumulated Amortization	(292,500)	(300,906)
Net Carrying Amount	233,649	144,133
Software & technology
Finite lived intangible assets
Gross Carrying Amount	173,141	150,037
Accumulated Amortization	(144,742)	(136,508)
Net Carrying Amount	28,399	13,529
Trademarks & other
Finite lived intangible assets
Gross Carrying Amount	42,505	36,212
Accumulated Amortization	(32,367)	(28,702)
Net Carrying Amount	$ 10,138	$ 7,510