Income Taxes Repatriation (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Details of Repatriation of Foreign Earnings [Line Items]
Cash and Cash Equivalents	$ 438,000
Line of Credit Facility, Current Borrowing Capacity	500,000	$ 960,000
Foreign Earnings Repatriated	11,600
Foreign Tax Authority [Member]
Details of Repatriation of Foreign Earnings [Line Items]
Cash	276,000
Retained Earnings (Accumulated Deficit)	4,255
Income Tax Expense (Benefit)	17,000
Revolving Credit Facility [Member]
Details of Repatriation of Foreign Earnings [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 500,000