Investment Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 59,576	$ 165,688
Less than 12 months, unrealized losses	57	544
More than 12 months, fair value	81	0
More than 12 months, unrealized losses	1	0
Fair Value	59,657	165,688
Accumulated In Investments	58	544
U.S. Treasury and government sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	56,109	165,004
Less than 12 months, unrealized losses	52	539
More than 12 months, fair value	0	0
More than 12 months, unrealized losses	0	0
Fair Value	56,109	165,004
Accumulated In Investments	52	539
Municipal Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	3,142
Less than 12 months, unrealized losses	4
More than 12 months, fair value	81
More than 12 months, unrealized losses	1
Fair Value	3,223
Accumulated In Investments	5
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	325	567
Less than 12 months, unrealized losses	1	4
More than 12 months, fair value	0	0
More than 12 months, unrealized losses	0	0
Fair Value	325	567
Accumulated In Investments	$ 1	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