Fair Value Measurements (Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation) (Details) (Contingent Consideration Liability, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Contingent Consideration Liability
Contingent consideration for acquisitions
Balance at beginning of period	$ (7,860)	$ (6,544)	$ (8,527)	$ (7,577)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments	0	3,425	691	3,425
Fair value adjustment	0	62	0	892
Foreign currency translation adjustment	0	(114)	(24)	89
Balance at end of period	$ (7,860)	$ (3,171)	$ (7,860)	$ (3,171)