Shareholders' Equity (Components of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Activity Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	$ (63,036)	$ 7,711	$ (2,878)
Other comprehensive income (loss) during the period, net of tax, before reclassification	24,211	(75,635)	10,041
Amount reclassified from accumulated other comprehensive income (loss), net of tax	1,493	4,888	548
Total other comprehensive income (loss)	25,704	(70,747)	10,589
Balance at end of period	(37,332)	(63,036)	7,711
Accumulated Unrealized (Losses) Gains on Securities
Activity Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(53,665)	6,710	4,204
Other comprehensive income (loss) during the period, net of tax, before reclassification	43,828	(62,182)	5,461
Amount reclassified from accumulated other comprehensive income (loss), net of tax	304	1,807	(2,955)
Total other comprehensive income (loss)	44,132	(60,375)	2,506
Balance at end of period	(9,533)	(53,665)	6,710
Accumulated Unrealized Losses on Derivative Instruments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(2,462)	(5,292)	(7,082)
Other comprehensive income (loss) during the period, net of tax, before reclassification	(1,244)	(251)	(1,713)
Amount reclassified from accumulated other comprehensive income (loss), net of tax	1,189	3,081	3,503
Total other comprehensive income (loss)	(55)	2,830	1,790
Balance at end of period	(2,517)	(2,462)	(5,292)
Accumulated Foreign Currency Translation Adjustments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(6,909)	6,293	0
Other comprehensive income (loss) during the period, net of tax, before reclassification	(18,373)	(13,202)	6,293
Amount reclassified from accumulated other comprehensive income (loss), net of tax	0	0	0
Total other comprehensive income (loss)	(18,373)	(13,202)	6,293
Balance at end of period	$ (25,282)	$ (6,909)	$ 6,293