Fair Value Measurements (Summary of Changes in Level 3 Liabilities) (Details) - Contingent Consideration [Member] - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Changes in Level 3 liabilities measured at fair value on recurring basis
Beginning balance	$ 26,334	$ 25,560	$ 24,814	$ 50,328	$ 48,395	$ 46,022
Fair value adjustments included in other income (expense), net	(153)	774	746	26	2,162	3,404
Contingent consideration settled				(25,170)	(229)	(1,031)
Ending balance	$ 26,181	$ 26,334	$ 25,560	$ 25,184	$ 50,328	$ 48,395