Commitments and Contingencies - Additional Information (Detail) $ in Millions	Jun. 30, 2019 USD ($) EquityFund
Contingencies And Commitments [Line Items]
Number of private equity funds | EquityFund	2
Commitments towards private equity funds	$ 7.7
Investment Commitments [Member]
Contingencies And Commitments [Line Items]
Aggregate investment committed in private equity funds	$ 7.9