Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Unrealized gain on derivative instruments	$ 1,478	$ 930
Liabilities
Contingent consideration	10,323	12,545
Level 1
Assets
Unrealized gain on derivative instruments	0	0
Liabilities
Contingent consideration	0	0
Level 2
Assets
Unrealized gain on derivative instruments	1,478	930
Liabilities
Contingent consideration	0	0
Level 3
Assets
Unrealized gain on derivative instruments	$ 0	0
Liabilities
Contingent consideration		$ 12,545