Goodwill and Intangible Assets (Details Textuals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 968,844	$ 929,168
Ahmann and Martin Company [Member]
Business Acquisition [Line Items]
Goodwill acquired during period	40,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Additions to finite-lived intangible assets	$ 12,000