Investments Investment Securities in Unrealized Loss Position (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 304,031
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(3,174)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	62,566
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(2,986)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	366,597
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(6,160)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	94
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	77,631
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(364)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	77,631
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss	(364)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	8
US Government and Government Agencies and Authorities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	10,375
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(90)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	634
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(59)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	11,009
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(149)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	2
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	145,826
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(846)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	145,826
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(846)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	15
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	71,930
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(1,133)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	4,372
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(132)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	76,302
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(1,265)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	40
Mortgage Backed Securities, Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	75,879
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(1,102)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	57,553
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(2,792)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	133,432
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(3,894)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	33
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	77,631
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(364)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	77,631
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss	(364)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	8
Other Aggregated Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	21
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(3)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	7
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(3)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	28
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ (6)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	4