Derivative Financial Instruments (Assets and liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014
Derivative Financial Instruments Not Designated as Hedging Instruments
Asset Derivatives	$ 16,473	$ 16,515
Liability Derivatives	16,320	16,755
Interest Rate Lock Commitments
Derivative Financial Instruments Not Designated as Hedging Instruments
Asset Derivatives	303	152
Liability Derivatives	0	0
Forward Commitments
Derivative Financial Instruments Not Designated as Hedging Instruments
Asset Derivatives	1	0
Liability Derivatives	8	13
Interest Rate Swap Agreements
Derivative Financial Instruments Not Designated as Hedging Instruments
Asset Derivatives	16,152	16,262
Liability Derivatives	16,185	16,296
Foreign Exchange Contracts
Derivative Financial Instruments Not Designated as Hedging Instruments
Asset Derivatives	17	101
Liability Derivatives	127	446
Conversion Rate Swap Agreement
Derivative Financial Instruments Not Designated as Hedging Instruments
Liability Derivatives			$ 100