Goodwill and Other Intangible Assets (Details 2) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 455,052	$ 189,996
Finite-Lived Intangible Assets, Accumulated Amortization	(56,409)	(39,018)
Finite-lived intangible assets, net	398,643	150,978	$ 162,223	$ 173,065
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	424,000	187,114
Finite-Lived Intangible Assets, Accumulated Amortization	(49,717)	(36,601)
Finite-lived intangible assets, net	374,283	150,513
Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	30,000	0
Finite-Lived Intangible Assets, Accumulated Amortization	(6,250)	0
Finite-lived intangible assets, net	23,750	0
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	52	421
Finite-Lived Intangible Assets, Accumulated Amortization	(42)	(366)
Finite-lived intangible assets, net	10	55
Customer Contracts [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,000	0
Finite-Lived Intangible Assets, Accumulated Amortization	(400)	0
Finite-lived intangible assets, net	600	0
Unpatented Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0	2,461
Finite-Lived Intangible Assets, Accumulated Amortization	0	(2,051)
Finite-lived intangible assets, net	$ 0	$ 410