Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
Increase (Reduction) in Rate Resulting from [Abstract]
State taxes, net of federal benefit	2.21%	2.38%	2.08%
Foreign rate differential	(0.32%)	(0.33%)	(0.45%)
Federal tax credits	(0.29%)	(0.32%)	(0.51%)
Dividends received deduction	(0.03%)	(0.03%)	(0.03%)
Other	(0.11%)	(0.40%)	(0.89%)
Actual tax expense of operations	36.46%	36.30%	35.20%