Goodwill and Intangible Assets Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 87,385	$ 23,286
Finite-Lived Intangible Assets, Accumulated Amortization		(22,437)	(10,915)
Finite-Lived Intangible Assets, Net		64,948	12,371
Indefinite-lived Intangible Assets Acquired		3,555	3,307
Value of Business Acquired
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		42,788	8,975
Finite-Lived Intangible Assets, Accumulated Amortization		(17,428)	(7,867)
Finite-Lived Intangible Assets, Net		25,360	1,108
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		34,661	10,284
Finite-Lived Intangible Assets, Accumulated Amortization		(4,422)	(2,784)
Finite-Lived Intangible Assets, Net		30,239	$ 7,500
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	8 years 4 months		3 years 8 months
Trade Names
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		6,381	$ 720
Finite-Lived Intangible Assets, Accumulated Amortization		(587)	(264)
Finite-Lived Intangible Assets, Net		$ 5,794	$ 456
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 5 months		2 years 1 month