Accumulated Other Comprehensive Income (Changes in AOCI by Component) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 5,621	[1]	$ (12,044)	[1]
Other comprehensive income (loss) before reclassifications	9,096	[1]	7,119	[1]
Amounts reclassified from accumulated other comprehensive income (loss) (2)	(431)	[1],[2]	(118)	[1],[2]
Net current-period other comprehensive income (loss)	8,665	[1]	7,001	[1]
Ending balance	14,286	[1]	(5,043)	[1]
Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	7,462	[1]	(10,108)	[1]
Other comprehensive income (loss) before reclassifications	9,376	[1]	7,119	[1]
Amounts reclassified from accumulated other comprehensive income (loss) (2)	(459)	[1],[2]	(142)	[1],[2]
Net current-period other comprehensive income (loss)	8,917	[1]	6,977	[1]
Ending balance	16,379	[1]	(3,131)	[1]
Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,841)	[1]	(1,936)	[1]
Other comprehensive income (loss) before reclassifications	(280)	[1]	0	[1]
Amounts reclassified from accumulated other comprehensive income (loss) (2)	28	[1],[2]	24	[1],[2]
Net current-period other comprehensive income (loss)	(252)	[1]	24	[1]
Ending balance	$ (2,093)	[1]	$ (1,912)	[1]

[1] All amounts are net of tax. Amounts in parenthesis indicate debits.

[2] See following table for details about these reclassifications.