Accumulated Other Comprehensive Income (Schedule Of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning of period	$ (9,233)	$ (53,842)
Other comprehensive income (loss) before reclassifications	2,938	679
Gains reclassified from accumulated other comprehensive income	(1,162)	1,585
Balance end of period	51,870	(48,983)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning of period	(41,791)	(36,470)
Balance end of period	(40,015)	(34,206)
Unrealized (Loss) Gain on Investments, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning of period	(157)	(22)
Other comprehensive income (loss) before reclassifications	407	118
Gains reclassified from accumulated other comprehensive income	0	0
Balance end of period	250	96
Unrealized Gain (Loss) on Derivative Instruments, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning of period	7,589	(5,219)
Other comprehensive income (loss) before reclassifications	2,474	(2,388)
Gains reclassified from accumulated other comprehensive income	(1,162)	1,585
Balance end of period	8,901	(6,022)
Unrealized (Loss) Gain on Net Investment Hedge, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning of period	(394)	(4,311)
Other comprehensive income (loss) before reclassifications	1,480	(2,216)
Gains reclassified from accumulated other comprehensive income	0	0
Balance end of period	1,086	(6,527)
Cumulative Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning of period	(48,829)	(26,918)
Other comprehensive income (loss) before reclassifications	(1,423)	5,165
Gains reclassified from accumulated other comprehensive income	0	0
Balance end of period	$ (50,252)	$ (21,753)