Investment Securities - Unrealized Gain (Loss) on Investments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 43,263	$ 165,688
Less than 12 months, unrealized losses	50	544
More than 12 months, fair value	0	0
More than 12 months, unrealized losses	0	0
Fair Value	43,263	165,688
Accumulated In Investments	50	544
U.S. Treasury and government sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	42,883	165,004
Less than 12 months, unrealized losses	47	539
More than 12 months, fair value	0	0
More than 12 months, unrealized losses	0	0
Fair Value	42,883	165,004
Accumulated In Investments	47	539
Municipal Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	208
Less than 12 months, unrealized losses	1
More than 12 months, fair value	0
More than 12 months, unrealized losses	0
Fair Value	208
Accumulated In Investments	1
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	172	567
Less than 12 months, unrealized losses	2	4
More than 12 months, fair value	0	0
More than 12 months, unrealized losses	0	0
Fair Value	172	567
Accumulated In Investments	2	4
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value		117
Less than 12 months, unrealized losses		1
More than 12 months, fair value		0
More than 12 months, unrealized losses		0
Fair Value		117
Accumulated In Investments		$ 1

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

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This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

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