Commitments and Contingencies - Additional Information (Detail) $ in Millions	Mar. 31, 2020 USD ($)
June 1, 2019 - May 31, 2020 [Member]
Reinsurance Retention Policy [Line Items]
Reinsurance payable, next twelve months	$ 118.9
June 1, 2020 - May 31, 2021 [Member]
Reinsurance Retention Policy [Line Items]
Reinsurance payable, due in second year	$ 84.3

Minimum amount of other commitment maturing in the next fiscal year following the latest fiscal year for commitments not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in this taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitmentDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant