Basis of Preparation and Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income (Loss) - Additional Information (Detail) - USD ($)	12 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Accounting Policies [Abstract]
Reclassifications out of accumulated other comprehensive income (loss)	$ 0	$ 0	$ 0

Amount after tax of reclassification adjustments of other comprehensive income (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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