Business Combinations (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended	12 Months Ended
	Nov. 10, 2015	Oct. 29, 2015	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Business acquisition, date of acquisition agreement		Oct. 29, 2015
Business acquisition, name of acquired entity				Gazelle, Inc.
Business acquisition, effective date of acquisition	Nov. 10, 2015
Bargain purchase gain	$ 989			$ 989	$ 0	$ 0
Business combination, income tax rate used for pro forma				5.80%	4.10%	3.90%
Gazelle Inc.
Business Acquisition [Line Items]
Business combination, income tax rate used for pro forma				37.50%
General and administrative expense
Business Acquisition [Line Items]
Business combination, acquisition related costs			$ 300