Indebtedness (Money Market Loans Narrative) (Details) (USD $)	3 Months Ended
	Jun. 30, 2012
Agreement Expiring In September 2012 [Member]
Debt Instrument [Line Items]
Money market loans maximum amount allowed	$ 35,000,000
Money market advances agreement expiration	September 30, 2012
Money market loans, terms	generally overnight or for up to seven days
Short-term advances outstanding	0
Agreement Expiring In January 2013 [Member]
Debt Instrument [Line Items]
Money market loans maximum amount allowed	35,000,000
Money market advances agreement expiration	January 2, 2013
Money market loans, terms	one to six months with rates at a fixed spread over the corresponding London Interbank Offering Rate
Short-term advances outstanding	$ 0
Maximum [Member] | Agreement Expiring In September 2012 [Member]
Debt Instrument [Line Items]
Short term debt maturity period	7 days
Maximum [Member] | Agreement Expiring In January 2013 [Member]
Debt Instrument [Line Items]
Short term debt maturity period	6 months
Minimum [Member] | Agreement Expiring In January 2013 [Member]
Debt Instrument [Line Items]
Short term debt maturity period	1 month