Acquisitions (Details) $ in Thousands		3 Months Ended	9 Months Ended		12 Months Ended
	Feb. 17, 2015 USD ($)	Mar. 31, 2016 USD ($) acquisition	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Common stock issued in acquisition			$ 0	$ 43,530
Goodwill acquired during period		$ 3,000
Additions to finite-lived intangible assets		$ 1,000			$ 12,000
Number of acquisitions | acquisition		2
Ahmann and Martin Company [Member]
Business Acquisition [Line Items]
Common stock issued in acquisition	$ 48,000
Maximum contingent consideration	$ 8,000
Goodwill acquired during period					40,000
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Additions to finite-lived intangible assets			$ 1,012		$ 12,115