Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
Increase (reduction) in rate resulting from:
State taxes, net of federal benefit	2.38%	2.08%	2.70%
Foreign rate differential	(0.33%)	(0.45%)	(0.55%)
Federal tax credits	(0.32%)	(0.51%)	(0.21%)
Interest on deferred tax	0.00%	0.00%	0.12%
Dividends received deduction	(0.03%)	(0.03%)	(0.06%)
Other	(0.40%)	(0.89%)	(0.07%)
Actual tax expense of operations	36.30%	35.20%	36.93%