Commitments and Contingencies - Operating Leases - Additional Information (Detail) - ft²			1 Months Ended		3 Months Ended
	Oct. 01, 2018	Aug. 01, 2018	May 31, 2018	Apr. 30, 2018	Mar. 31, 2018
Operating Lease One [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease					54,943
Lease expire date					Aug. 15, 2024
Operating Lease Two [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease				40,419	19,805
Lease expire date				Aug. 31, 2024	Feb. 28, 2022
Increased office space rent				20,614
Operating Lease Two [Member] | Scenario Forecast [Member]
Commitments And Contingencies [Line Items]
Increased office space rent	7,133
Operating Lease Two [Member] | Subsequent Event [Member]
Commitments And Contingencies [Line Items]
Increased office space rent		13,481
Operating Lease Three [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease			15,525
Lease expire date			Nov. 30, 2024