Background and Basis of Presentation - Additional Information (Details)	6 Months Ended
	Sep. 30, 2020 Segment
Background And Basis Of Presentation [Line Items]
Number of reportable segments	2
Defined benefit plan percentage of fair value of investments of other pension assets	56.00%
Amortization period of gains and losses on other plan assets to be amortized into earnings	5 years
Change in Accounting Principle [Member]
Background And Basis Of Presentation [Line Items]
Defined benefit plan percentage of fair value of investments of fixed income assets	44.00%
ASU 2016-13 [Member]
Background And Basis Of Presentation [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Apr. 01, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
ASU 2018-13 [Member]
Background And Basis Of Presentation [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Apr. 01, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true