Fair Value Measurements (Summary of Changes in Level 3 Liabilities) (Details) (Contingent consideration [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended						9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2014 Minimum [Member[	Sep. 30, 2014 Maximum [Member]
Changes in Level 3 liabilities measured at fair value on recurring basis
Beginning balance	$ 50,328	$ 48,395	$ 46,022	$ 47,918	$ 44,004	$ 42,624
Fair value adjustments included in other income (expense), net	26	2,162	3,404	9,195	3,914	1,380
Fair value measured at conclusion of purchase price analysis measurement period				759
Contingent consideration settled	(25,170)	(229)	(1,031)
Ending balance	$ 25,184	$ 50,328	$ 48,395	$ 57,872	$ 47,918	$ 44,004
Fair value inputs, discount rate (as a percent)							14.00%	18.00%