Comprehensive Income (Schedule of Changes in the Components of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	$ 1,051	$ 6,935
Other comprehensive income (loss) before reclassifications	29,310	(4,289)
Amounts reclassified from accumulated other comprehensive income (loss)	(18,694)	(1,595)
Net other comprehensive income (loss)	10,616	(5,884)	3,834
Purchase of shares from noncontrolling interest	(591)
Balance	11,076	1,051	6,935
Accumulated Net Unrealized Investment Gain (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(528)	5,444
Other comprehensive income (loss) before reclassifications	33,759	(4,377)
Amounts reclassified from accumulated other comprehensive income (loss)	(18,694)	(1,595)
Net other comprehensive income (loss)	15,065	(5,972)
Purchase of shares from noncontrolling interest	0
Balance	14,537	(528)
Accumulated Defined Benefit Plans Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	140	52
Other comprehensive income (loss) before reclassifications	(127)	88
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Net other comprehensive income (loss)	(127)	88
Purchase of shares from noncontrolling interest	0
Balance	13	140
Accumulated Translation Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	1,439	1,439
Other comprehensive income (loss) before reclassifications	(4,322)	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Net other comprehensive income (loss)	(4,322)	0
Purchase of shares from noncontrolling interest	(591)
Balance	$ (3,474)	$ 1,439