Fair Value (Activity Under Level 3, Fair Value Measurements Using Significant Unobservable Inputs By Asset Type) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 2,532	$ 12,380	$ 4,018	$ 45,673
Total gains or (losses) (realized/unrealized), Included in earnings	1,237	55	1,312	(578)
Total gains or (losses) (realized/unrealized), Included in other comprehensive income (loss)	(295)	(135)	(222)	(911)
Purchases, issuances and settlements	22,783	(2,129)	21,149	617
Transfers in and/or (out) of Level 3	(1,101)	(5,358)	(1,101)	(39,988)
Ending balance	25,156	4,813	25,156	4,813
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total gains or (losses) (realized/unrealized), Included in other comprehensive income (loss)	42		42
Purchases, issuances and settlements	1,274		1,274
Ending balance	1,316		1,316
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Asset-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	2,528	4,832	3,533	4,849
Total gains or (losses) (realized/unrealized), Included in earnings	1,235	58	1,291	74
Total gains or (losses) (realized/unrealized), Included in other comprehensive income (loss)	(284)	(186)	(191)	(515)
Purchases, issuances and settlements	17,898	(377)	16,744	(397)
Transfers in and/or (out) of Level 3	(1,101)		(1,101)	316
Ending balance	20,276	4,327	20,276	4,327
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Foreign Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance		7,225	481	11,421
Total gains or (losses) (realized/unrealized), Included in earnings		(4)	18	(655)
Total gains or (losses) (realized/unrealized), Included in other comprehensive income (loss)	(50)	51	(70)	(371)
Purchases, issuances and settlements	3,614	(1,751)	3,135	1,086
Transfers in and/or (out) of Level 3		(5,039)		(10,999)
Ending balance	3,564	482	3,564	482
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Non-Agency Residential Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	4	323	4	5
Total gains or (losses) (realized/unrealized), Included in earnings	2	1	3	3
Total gains or (losses) (realized/unrealized), Included in other comprehensive income (loss)	(3)		(3)	(25)
Purchases, issuances and settlements	(3)	(1)	(4)	(72)
Transfers in and/or (out) of Level 3		(319)		93
Ending balance		4		4
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Agency Residential Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance				29,398
Transfers in and/or (out) of Level 3				$ (29,398)