Financial Information (Schedule of Accounting Changes) (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
New Accounting Pronouncement Or Change In Accounting Principle Retrospective Adjustments Abstract
Other Assets	$ 1,355,046,000	$ 1,355,046,000	$ 1,385,572,000
Other Liabilities	551,615,000	551,615,000	649,359,000
Undivided profits	816,483,000	816,483,000	851,585,000
Other expense	59,459,000	59,883,000
Provision/(benefit) for income taxes	16,842,000	70,486,000
Net Income (Loss) Available to Common Stockholders, Basic	$ 46,073,000	$ 169,209,000
Diluted income/(loss) per share available to common shareholders	$ 0.19	$ 0.71
Accounting Standards Update 201401 [Member]
New Accounting Pronouncement Or Change In Accounting Principle Retrospective Adjustments Abstract
Other Assets	$ (4,190,000)	$ (4,190,000)	(4,700,000)	$ (5,340,000)
Other Liabilities	5,937,000	5,937,000	4,678,000	7,034,000
Undivided profits	(10,127,000)	(10,127,000)	(9,378,000)	(12,374,000)
Other expense	(2,170,000)	(6,510,000)	(8,680,000)	(10,082,000)	$ (14,177,000)
Provision/(benefit) for income taxes	1,421,000	4,263,000	5,684,000	12,780,000	13,234,000
Net Income (Loss) Available to Common Stockholders, Basic	$ 749,000	$ 2,247,000	$ 2,996,000	$ (2,698,000)	$ 943,000
Diluted income/(loss) per share available to common shareholders	$ 0	$ 0.01	$ 0.01	$ (0.01)	$ 0