Investment Securities - Unrealized Gain (Loss) on Investments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Less than Twelve Months, Fair Value	$ 111,660	$ 134,224
Less Than 12 Months Aggregate Losses, Accumulated In Investments	176	397
Twelve Months or Longer, Fair Value	0	0
12 Months Or Longer, Aggregate Losses Accumulated In Investments	0	0
Fair Value	111,660	134,224
Accumulated In Investments	176	397
U.S. Treasury and government sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less than Twelve Months, Fair Value	110,947	122,560
Less Than 12 Months Aggregate Losses, Accumulated In Investments	165	323
Twelve Months or Longer, Fair Value	0	0
12 Months Or Longer, Aggregate Losses Accumulated In Investments	0	0
Fair Value	110,947	122,560
Accumulated In Investments	165	323
U.S. Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than Twelve Months, Fair Value	390
Less Than 12 Months Aggregate Losses, Accumulated In Investments	8
Twelve Months or Longer, Fair Value	0
12 Months Or Longer, Aggregate Losses Accumulated In Investments	0
Fair Value	390
Accumulated In Investments	8
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than Twelve Months, Fair Value	323	5,613
Less Than 12 Months Aggregate Losses, Accumulated In Investments	3	54
Twelve Months or Longer, Fair Value	0	0
12 Months Or Longer, Aggregate Losses Accumulated In Investments	0	0
Fair Value	323	5,613
Accumulated In Investments	3	54
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Less than Twelve Months, Fair Value		6,051
Less Than 12 Months Aggregate Losses, Accumulated In Investments		20
Twelve Months or Longer, Fair Value		0
12 Months Or Longer, Aggregate Losses Accumulated In Investments		0
Fair Value		6,051
Accumulated In Investments		$ 20