Comprehensive Income (Changes in Accumulated Other Comprehensive Loss by Component) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	$ (8,154)
Other comprehensive income before reclassifications	2,335
Amounts reclassified from accumulated other comprehensive loss	336
Other comprehensive income (loss)	2,671	$ (4,068)
Balance at March 31, 2019	(5,483)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(2,946)
Other comprehensive income before reclassifications	0
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income (loss)	0
Balance at March 31, 2019	(2,946)
Unrealized Loss on Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(2,440)
Other comprehensive income before reclassifications	2,188
Amounts reclassified from accumulated other comprehensive loss	(558)
Other comprehensive income (loss)	1,630
Balance at March 31, 2019	(810)
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(985)
Other comprehensive income before reclassifications	147
Amounts reclassified from accumulated other comprehensive loss	894
Other comprehensive income (loss)	1,041
Balance at March 31, 2019	56
Other Comprehensive Loss on Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(1,783)
Other comprehensive income before reclassifications	0
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income (loss)	0
Balance at March 31, 2019	$ (1,783)