Accounting for Share-Based Compensation 5 (Details) - $ / shares shares in Millions		3 Months Ended			6 Months Ended
		Sep. 30, 2016		Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restricted Stock Awards (RSAs)
Summary of all RSAs and RSUs granted, including grants made pursuant to long-term incentive plans
Shares		0.0	[1]	0.1	2.9	2.8
Weighted average grant date fair value (in dollars per share)	[2]	$ 34.31		$ 29.86	$ 31.55	$ 30.64
Restricted Stock Units (RSUs)
Summary of all RSAs and RSUs granted, including grants made pursuant to long-term incentive plans
Shares		0.0	[1]	0.1	1.0	0.9
Weighted average grant date fair value (in dollars per share)	[3]	$ 31.82		$ 27.72	$ 30.16	$ 28.72

[1] Less than 0.1 million.

[2] The fair value is based on the quoted market value of the Company’s common stock on the grant date.

[3] The fair value is based on the quoted market value of the Company’s common stock on the grant date reduced by the present value of dividends expected to be paid on the Company’s common stock prior to vesting of the RSUs, which is calculated using a risk-free interest rate.