Business Combinations (Pro Forma) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition, Pro Forma Information
Revenue	$ 66,813	$ 50,808	$ 195,278	$ 153,688
Net income	$ 20,232	$ 18,015	$ 57,604	$ 47,011
Basic EPS	$ 0.59	$ 0.47	$ 1.65	$ 1.23
Diluted EPS	$ 0.59	$ 0.47	$ 1.63	$ 1.22
Revenue, Net, Increase (Decrease)	$ 16,005
Revenue, Net, Increase (Decrease), Percentage	31.50%
Curepet, Inc. [Member]
Business Acquisition, Pro Forma Information
Revenue		$ 325	$ 80
Parent, Curepet , Healthcare Magic, Vertex, Oakstone, and i3 Combined [Member]
Business Acquisition, Pro Forma Information
Revenue, pro forma	$ 66,813	69,642	202,031	$ 209,622
Net income, pro forma	$ 20,232	$ 17,711	$ 57,834	$ 47,075
Basic EPS, pro forma	$ 0.59	$ 0.47	$ 1.65	$ 1.23
Diluted EPS, pro forma	$ 0.59	$ 0.46	$ 1.64	$ 1.22
Business Acquisition, Pro Forma Revenue, Increase (Decrease), Percentage	(4.10%)
Impact of Currency Rates [Member]
Business Acquisition, Pro Forma Information
Revenue, Net, Increase (Decrease)	$ (3,400)