Shareholders’ Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning of period	$ 88,581	$ 120,683	$ 197,198
Unrealized gains (losses), net of tax effects of $4, $10, and $0	8	(1,303)	(955)
Net current period other comprehensive income	2,098	(2,165)	(4,228)
Accumulated other comprehensive loss balance, end of period	79,173	88,581	120,683
Total accumulated other comprehensive loss, end of period	(59,547)	(61,645)	(59,480)
Investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning of period	(6)	1,297	2,252
Unrealized gains (losses), net of tax effects of $4, $10, and $0	8	1,647	(562)
Reclassification adjustments for losses (gains) included in other income (expense)	0	(2,950)	(393)
Net current period other comprehensive income	8	(1,303)	(955)
Accumulated other comprehensive loss balance, end of period	2	(6)	1,297
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Unrealized gains (losses), tax effects	4	10	0
Reclassification adjustments for losses (gains) included in other income (expense), tax effects	0	0	0
Foreign currency translation
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning of period	(61,639)	(60,777)	(57,504)
Translation adjustments	2,090	(1,134)	(3,009)
Reclassification adjustments for losses (gains) included in other income (expense)	0	272	(264)
Net current period other comprehensive income	2,090	(862)	(3,273)
Accumulated other comprehensive loss balance, end of period	$ (59,549)	$ (61,639)	$ (60,777)