Other-Than-Temporary Impairment Losses (Activity Related To The Credit Component Recognized In Earnings On Debt Securities) (Details) (Non-Agency Mortgage-Backed Securities [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Non-Agency Mortgage-Backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Balance, April 1, 2012	$ 96	$ 113
Additions for the credit component on debt securities in which other-than-temporary impairment was not previously recognized	17
Balance, June 30, 2012		$ 113