Investments (Purchased Credit Impaired Investments) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Certain Loans Acquired in Transfer Accounted for as Available-for-sale Debt Securities, Acquired [Abstract]
Contractually required payments (including interest)	$ 31,672		$ 91,863
Cash flows expected to be collected	25,722	[1]	72,940	[1]
Fair value of investments acquired	$ 18,151		$ 50,874

[1] Represents undiscounted principal and interest cash flow expectations at the date of acquisition.