Fair Value of Financial Instruments (Details) - Level 2 - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Market Approach Valuation Technique [Member] | Junior subordinated notes
Financial Instruments Not Measured at Fair Value
Market interest rate (as a percent)	6.53%	6.84%
Market Approach Valuation Technique [Member] | Mortgages [Member] | Minimum [Member]
Financial Instruments Not Measured at Fair Value
Market interest rate (as a percent)	2.13%	2.13%
Market Approach Valuation Technique [Member] | Mortgages [Member] | Maximum [Member]
Financial Instruments Not Measured at Fair Value
Market interest rate (as a percent)	9.26%	9.38%
Carrying and Fair Value | Junior subordinated notes
Financial Instruments Not Measured at Fair Value
Estimated fair value lower than carrying value	$ 17.5	$ 21.8
Carrying and Fair Value | Mortgages [Member]
Financial Instruments Not Measured at Fair Value
Estimated fair value lower than carrying value	$ 4.8	$ 8.7