Business Combinations (Pro Forma) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition, Pro Forma Information
Revenue	$ 50,808	$ 50,293	$ 153,688	$ 153,863
Net income	18,015	13,143	47,011	44,029
Basic EPS	$ 0.47	$ 0.35	$ 1.23	$ 1.18
Diluted EPS	$ 0.47	$ 0.34	$ 1.22	$ 1.14
Revenue, Net, Increase (Decrease)	515		(175)
Revenue, Net, Increase (Decrease), Percentage	1.00%		(0.10%)
Parent, Qatarlyst, Curepet , Healthcare Magic Combined [Member]
Business Acquisition, Pro Forma Information
Revenue, pro forma	50,808	50,697	154,227	154,997
Net income, pro forma	18,015	12,587	46,975	43,430
Basic EPS, pro forma	$ 0.47	$ 0.33	$ 1.23	$ 1.16
Diluted EPS, pro forma	$ 0.47	$ 0.33	$ 1.22	$ 1.12
Business Acquisition, Pro Forma Revenue, Increase (Decrease)	111		(770)
Business Acquisition, Pro Forma Revenue, Increase (Decrease), Percentage	0.20%		(0.50%)
Impact of Currency Rates [Member]
Business Acquisition, Pro Forma Information
Revenue, Net, Increase (Decrease)			$ 2,100