Investment Securities Available for Sale (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Market Value	$ 288,376		$ 288,376		$ 346,043
In loss position for Less than 12 months, Fair Value	9,159		9,159		151,724
In loss position for Less than 12 months, Unrealized Losses	(1,171)		(1,171)		(2,150)
In loss position for 12 months or more, Fair Value	0		0		15,934
In loss position for 12 months or more, Unrealized Losses	0		0		(1,529)
Total Fair Value	9,159		9,159		167,658
Total Unrealized Losses	1,171		1,171		3,679
Gross realized gains on sales	129	$ 100	13,601	$ 151
Gross realized losses on other-than-temporary impairments	(950)	(67)	(1,583)	(189)
Total net	(821)	33	12,018	(38)
Proceeds from investment securities sales	42,768	124,342	161,029	173,046
Proceeds from early redemptions by issuers	3,130	615	8,397	1,207
Gross realized losses on other-than-temporary impairments	(12,211)	$ 0	(12,211)	$ 0
Chief Executive Officer [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross realized losses on other-than-temporary impairments			(6,895)
Marketable equity securities
Schedule of Available-for-sale Securities [Line Items]
Market Value	106,976		106,976		154,192
In loss position for Less than 12 months, Fair Value	9,159		9,159		6,599
In loss position for Less than 12 months, Unrealized Losses	(1,171)		(1,171)		(138)
In loss position for 12 months or more, Fair Value	0		0		3,534
In loss position for 12 months or more, Unrealized Losses	0		0		(966)
Total Fair Value	9,159		9,159		10,133
Total Unrealized Losses	1,171		1,171		1,104
Mutual funds invested in fixed income securities
Schedule of Available-for-sale Securities [Line Items]
Market Value	54,864		54,864		59,826
In loss position for Less than 12 months, Fair Value					59,826
In loss position for Less than 12 months, Unrealized Losses					(1,659)
In loss position for 12 months or more, Fair Value					0
In loss position for 12 months or more, Unrealized Losses					0
Total Fair Value					59,826
Total Unrealized Losses					1,659
U.S. Government securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	0		0
1 Year up to 5 Years	35,433		35,433
More than 5 Years	0		0
Market Value	35,433		35,433
In loss position for Less than 12 months, Fair Value					22,375
In loss position for Less than 12 months, Unrealized Losses					(18)
In loss position for 12 months or more, Fair Value					0
In loss position for 12 months or more, Unrealized Losses					0
Total Fair Value					22,375
Total Unrealized Losses					18
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	6,917		6,917
1 Year up to 5 Years	47,565		47,565
More than 5 Years	259		259
Market Value	54,741		54,741
In loss position for Less than 12 months, Fair Value					30,896
In loss position for Less than 12 months, Unrealized Losses					(204)
In loss position for 12 months or more, Fair Value					7,224
In loss position for 12 months or more, Unrealized Losses					(131)
Total Fair Value					38,120
Total Unrealized Losses					335
U.S. mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	1,061		1,061
1 Year up to 5 Years	5,132		5,132
More than 5 Years	158		158
Market Value	6,351		6,351
In loss position for Less than 12 months, Fair Value					3,370
In loss position for Less than 12 months, Unrealized Losses					(26)
In loss position for 12 months or more, Fair Value					0
In loss position for 12 months or more, Unrealized Losses					0
Total Fair Value					3,370
Total Unrealized Losses					26
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	6,632		6,632
1 Year up to 5 Years	1,793		1,793
More than 5 Years	6,112		6,112
Market Value	14,537		14,537
In loss position for Less than 12 months, Fair Value					11,332
In loss position for Less than 12 months, Unrealized Losses					(46)
In loss position for 12 months or more, Fair Value					5,176
In loss position for 12 months or more, Unrealized Losses					(432)
Total Fair Value					16,508
Total Unrealized Losses					478
U.S. asset backed securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	2,342		2,342
1 Year up to 5 Years	10,343		10,343
More than 5 Years	675		675
Market Value	13,360		13,360
In loss position for Less than 12 months, Fair Value					15,228
In loss position for Less than 12 months, Unrealized Losses					(29)
In loss position for 12 months or more, Fair Value					0
In loss position for 12 months or more, Unrealized Losses					0
Total Fair Value					15,228
Total Unrealized Losses					29
Index-linked U.S. bonds
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	0		0
1 Year up to 5 Years	2,114		2,114
More than 5 Years	0		0
Market Value	2,114		2,114
In loss position for Less than 12 months, Fair Value					2,098
In loss position for Less than 12 months, Unrealized Losses					(30)
In loss position for 12 months or more, Fair Value					0
In loss position for 12 months or more, Unrealized Losses					0
Total Fair Value					2,098
Total Unrealized Losses					$ 30
Marketable debt securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	16,952		16,952
1 Year up to 5 Years	102,380		102,380
More than 5 Years	7,204		7,204
Market Value	$ 126,536		$ 126,536