Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	(0.70%)	0.60%	0.90%
Change in classification of permanently reinvested earnings	0.00%	0.00%	1.40%
Change in valuation allowance on deferred tax assets	0.70%	(0.20%)	0.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense	8.60%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Deductions, Dividends	(1.80%)	0.00%	0.00%
Other, including changes in liabilities recorded for uncertain tax positions	(4.00%)	(3.20%)	(3.70%)
Effective income tax rate	37.80%	32.20%	33.60%