Fair Value Measurements Fair Value Measurements (Change in Contingent Consideration) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 1,737		$ 2,986	$ 2,047	[1]	$ 2,945
Change in fair value of contingent consideration	0		(939)	(310)		(898)
Payments	0		0	0		0
Balance at end of period	$ 1,737	[1]	$ 2,047	$ 1,737	[1]	$ 2,047

[1] The contingent consideration liability is included in other liabilities in the Unaudited Consolidated Balance Sheets.