Derivative Instruments And Hedging Activities (Narrative) (Details) (USD $)	12 Months Ended						3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2014 Interest Rate Lock Commitments [Member]	Mar. 31, 2013 Interest Rate Lock Commitments [Member]	Mar. 31, 2012 Interest Rate Lock Commitments [Member]	Sep. 30, 2011 Cash Flow Hedging [Member] Interest Rate Lock Commitments [Member]	Jul. 30, 2010 Cash Flow Hedging [Member] Interest Rate Lock Commitments [Member]	Mar. 31, 2014 Fair Value Hedging [Member] Interest Rate Swap [Member] derivative_instruments
Derivative Instruments and Hedging Activities [Line Items]
Derivative, notional amount								$ 100,000,000	$ 300,000,000
Derivative maturity date							Sep. 01, 2010		Oct. 01, 2013
Net gain (loss) on derivative instruments	517,000	517,000	517,000				(2,600,000)
Net gain (loss) on derivative instruments, after tax							(1,600,000)
Cash flow hedge loss reclassified to interest expense	75,361,000	70,077,000	68,846,000	517,000	517,000	517,000
Cash flow hedge loss to be reclassified within twelve months, gross				517,000
Cash flow hedge loss to be reclassified within twelve months, net of tax				326,000
Number of interest rate derivatives held									5
Derivative, amount of hedged item									300,000,000
Increase (decrease) in fair value of interest rate fair value hedging instruments									(2,500,000)
Increase (decrease) in fair value of hedged item in interest rate fair value hedge									$ 2,500,000
Fair value hedge ineffectiveness is immaterial	The net gain or loss recorded in earnings as a result of hedge ineffectiveness related to the designated fair value hedges was immaterial	The net gain or loss recorded in earnings as a result of hedge ineffectiveness related to the designated fair value hedges was immaterial	The net gain or loss recorded in earnings as a result of hedge ineffectiveness related to the designated fair value hedges was immaterial