Comprehensive Income (Changes in Accumulated Other Comprehensive Loss by Component) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	$ (8,154)
Other comprehensive income (loss) before reclassifications	1,991
Amounts reclassified from accumulated other comprehensive loss	1,036
Other comprehensive income	3,027	$ 2,652	$ 4,498
Balance at December 31, 2019	(5,127)	(8,154)
Foreign currency
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(2,946)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	0
Balance at December 31, 2019	(2,946)	(2,946)
Unrealized loss on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(2,440)
Other comprehensive income (loss) before reclassifications	2,881
Amounts reclassified from accumulated other comprehensive loss	(580)
Other comprehensive income	2,301
Balance at December 31, 2019	(139)	(2,440)
Unrealized (loss) gain on derivative instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(985)
Other comprehensive income (loss) before reclassifications	237
Amounts reclassified from accumulated other comprehensive loss	1,616
Other comprehensive income	1,853
Balance at December 31, 2019	868	(985)
Other comprehensive loss on pension liability
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018	(1,783)
Other comprehensive income (loss) before reclassifications	(1,127)
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	(1,127)
Balance at December 31, 2019	$ (2,910)	$ (1,783)