Fair Value Measurement Fair Value Measurement (Reconciliation of Level 3 Liabilities) (Details) - Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Balance, beginning of period	$ 5,708	$ 17,249	$ 7,665	$ 17,054	$ 17,054
Payments of contingent purchase obligations	1,360	4,804	3,317	4,804	4,804
Adjustments to contingent purchase obligation	(867)	(719)	(867)	(524)	(4,585)
Balance, end of period	$ 3,481	$ 11,726	$ 3,481	$ 11,726	$ 7,665