Accounting for Share-Based Compensation 4 (Details) - $ / shares shares in Millions		3 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
Restricted Stock Awards (RSAs)
Summary of all RSAs and RSUs granted, including grants made pursuant to long-term incentive plans
Shares		2.9	2.9
Weighted average grant date fair value (in dollars per share)	[1]	$ 31.69	$ 31.53
Restricted Stock Units (RSUs)
Summary of all RSAs and RSUs granted, including grants made pursuant to long-term incentive plans
Shares		1.1	1.0
Weighted average grant date fair value (in dollars per share)	[2]	$ 30.35	$ 30.10

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

[2] 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.