Earnings Per Share Information about Share Repurchase Plan (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Stock Repurchased and Retired During Period, Shares	2,946	572	9,117	3,761
Stock Repurchased and Retired During Period, Value	$ 90,001	$ 25,000	$ 291,674	$ 182,978
Repurchased And Retired Shares Excluded From Weighted Average Shares Outstanding	7,281	3,646	4,611	2,161