Accumulated Other Comprehensive Income (Changes in AOCI by Component) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (5,043)	[1]	$ 16,719	[1]	$ (12,044)	[1]	$ 20,149	[1]
Other comprehensive income before reclassifications	8,768	[1]	(25,930)	[1]	15,887	[1]	(29,179)	[1]
Amounts reclassified from accumulated other comprehensive loss (2)	(165)	[1],[2]	1	[1],[2]	(283)	[1],[2]	(180)	[1],[2]
Net current-period other comprehensive income	8,603	[1]	(25,929)	[1]	15,604	[1]	(29,359)	[1]
Ending balance	3,560	[1]	(9,210)	[1]	3,560	[1]	(9,210)	[1]
Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(3,131)	[1]	18,185	[1]	(10,108)	[1]	20,918	[1]
Other comprehensive income before reclassifications	8,768	[1]	(25,930)	[1]	15,887	[1]	(28,423)	[1]
Amounts reclassified from accumulated other comprehensive loss (2)	(189)	[1],[2]	(59)	[1],[2]	(331)	[1],[2]	(299)	[1],[2]
Net current-period other comprehensive income	8,579	[1]	(25,989)	[1]	15,556	[1]	(28,722)	[1]
Ending balance	5,448	[1]	(7,804)	[1]	5,448	[1]	(7,804)	[1]
Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,912)	[1]	(1,466)	[1]	(1,936)	[1]	(769)	[1]
Other comprehensive income before reclassifications	0	[1]	0	[1]	0	[1]	(756)	[1]
Amounts reclassified from accumulated other comprehensive loss (2)	24	[1],[2]	60	[1],[2]	48	[1],[2]	119	[1],[2]
Net current-period other comprehensive income	24	[1]	60	[1]	48	[1]	(637)	[1]
Ending balance	$ (1,888)	[1]	$ (1,406)	[1]	$ (1,888)	[1]	$ (1,406)	[1]

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

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