Employee Benefit Plans (Discount Rate Assumptions in Computation of Accumulated Postretirement Benefit Obligation) (Details)	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Accumulated postretirement benefit obligation	3.94%	3.89%	3.99%

The interest rate used to adjust for the time value of money for the plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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