Goodwill and Other Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized intangible assets
Original Cost	$ 188,089	$ 168,923
Accumulated Amortization	75,196	62,823
Net Book Value	112,893	106,100
Customer list
Amortized intangible assets
Original Cost	41,151	41,477
Accumulated Amortization	18,437	14,958
Net Book Value	22,714	26,519
Non-compete agreement
Amortized intangible assets
Original Cost	4,665	4,594
Accumulated Amortization	3,563	3,064
Net Book Value	1,102	1,530
Supply agreement
Amortized intangible assets
Original Cost	9,806	9,806
Accumulated Amortization	5,699	4,827
Net Book Value	4,107	4,979
Technology
Amortized intangible assets
Original Cost	15,500	15,500
Accumulated Amortization	5,616	4,243
Net Book Value	9,884	11,257
Trademarks and patents
Amortized intangible assets
Original Cost	18,185	18,717
Accumulated Amortization	5,882	4,335
Net Book Value	12,303	14,382
Lease intangible
Amortized intangible assets
Original Cost	12,420	5,514
Accumulated Amortization	5,707	4,969
Net Book Value	6,713	545
Software
Amortized intangible assets
Original Cost	84,339	71,362
Accumulated Amortization	28,372	24,592
Net Book Value	55,967	46,770
Other
Amortized intangible assets
Original Cost	2,023	1,953
Accumulated Amortization	1,920	1,835
Net Book Value	$ 103	$ 118