Earnings Per Share Information about Dilutive and Anti-Dilute Shares (Details) - shares shares in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		814
Antidilutive shares due to proceeds from exercising exceeded price of shares [Domain]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,454		1,319
2.5% Convertible Senior Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	14,205			14,205