Stock-Based Compensation (ESPP Purchase Option Assumptions) (Details) (Employee Stock Purchase Plan [Member])	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Valuation Assumption [Line Items]
Expected volatility	19.50%	23.20%	24.70%
Expected dividend yield	1.96%	2.19%	2.38%
Risk-free interest rate	0.10%	0.10%	0.10%
Minimum [Member]
Valuation Assumption [Line Items]
Expected term, months	3 months	3 months	3 months
Maximum [Member]
Valuation Assumption [Line Items]
Expected term, months	9 months	6 months	6 months