Changes In Accumulated Other Comprehensive Income (Loss) By Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	$ (122)	$ (8,118)
Other comprehensive income (loss) before reclassifications	(7,915)	10,070
Amounts reclassified from accumulated other comprehensive income to net income	53	(2,074)
Net current-period other comprehensive income (loss)	(7,862)	7,996
Accumulated other comprehensive income (loss), ending balance	(7,984)	(122)
Unrealized gains (losses), available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	1,142	(8,118)
Other comprehensive income (loss) before reclassifications	(5,797)	11,334
Amounts reclassified from accumulated other comprehensive income to net income	53	(2,074)
Net current-period other comprehensive income (loss)	(5,744)	9,260
Accumulated other comprehensive income (loss), ending balance	(4,602)	1,142
Foreign currency items, available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	0	0
Other comprehensive income (loss) before reclassifications	(584)	0
Amounts reclassified from accumulated other comprehensive income to net income	0	0
Net current-period other comprehensive income (loss)	(584)	0
Accumulated other comprehensive income (loss), ending balance	(584)	0
Total unrealized gains (losses), available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	1,142	(8,118)
Other comprehensive income (loss) before reclassifications	(6,381)	11,334
Amounts reclassified from accumulated other comprehensive income to net income	53	(2,074)
Net current-period other comprehensive income (loss)	(6,328)	9,260
Accumulated other comprehensive income (loss), ending balance	(5,186)	1,142
Unrealized loss on cash flow hedge
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	(1,264)	0
Other comprehensive income (loss) before reclassifications	(1,534)	(1,264)
Amounts reclassified from accumulated other comprehensive income to net income	0	0
Net current-period other comprehensive income (loss)	(1,534)	(1,264)
Accumulated other comprehensive income (loss), ending balance	$ (2,798)	$ (1,264)