Earnings Per Share (Narratives) (Details) - shares	6 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Post 1992 shares of the employee stock ownership plan that have not been committed to be released	18,885	21,219

Number of employee stock ownership plan (ESOP) shares that have not been committed to be released determined by relating the portion of time within a reporting period that these shares have been outstanding to the total time in that period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65882273&loc=d3e17400-113927

Name:	us-gaap_WeightedAverageNumberOfSharesEmployeeStockOwnershipPlanSharesNotCommittedToBeReleased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration