Comprehensive Income (Changes in Accumulated Other Comprehensive Loss by Component) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2015	$ (28,527)
Other comprehensive income (loss) before reclassifications	(736)
Amounts reclassified from accumulated other comprehensive loss	559
Other comprehensive (loss) income	(177)	$ 8,263	$ (41,741)
Balance at December 31, 2016	(28,704)	(28,527)
Foreign currency
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2015	(16,346)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive (loss) income	0
Balance at December 31, 2016	(16,346)	(16,346)
Unrealized loss on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2015	(2,900)
Other comprehensive income (loss) before reclassifications	996
Amounts reclassified from accumulated other comprehensive loss	(1,204)
Other comprehensive (loss) income	(208)
Balance at December 31, 2016	(3,108)	(2,900)
Unrealized loss on derivative instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2015	(2,255)
Other comprehensive income (loss) before reclassifications	(2,638)
Amounts reclassified from accumulated other comprehensive loss	1,763
Other comprehensive (loss) income	(875)
Balance at December 31, 2016	(3,130)	(2,255)
Other comprehensive loss on pension liability
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2015	(7,026)
Other comprehensive income (loss) before reclassifications	906
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive (loss) income	906
Balance at December 31, 2016	$ (6,120)	$ (7,026)