Acquisition (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 17, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Common stock issued in acquisition		$ 43,530	$ 0	$ 0
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		$ 12,115	$ 0	$ 0