Leases - Summary of Non-Cancellable Operating Leases, Primarily for Office Space and Certain Equipment (Detail) $ in Thousands	Sep. 30, 2019 USD ($)
Lessee Lease Description [Line Items]
Right-of-Use Asset	$ 13,648
Minneapolis, MN Lease [Member]
Lessee Lease Description [Line Items]
Remaining Term (years)	6 years
Right-of-Use Asset	$ 10,823
Little Falls, NJ Lease [Member]
Lessee Lease Description [Line Items]
Remaining Term (years)	4 years
Right-of-Use Asset	$ 1,674
Other Leases [Member]
Lessee Lease Description [Line Items]
Right-of-Use Asset	$ 1,151
Other Leases [Member] | Minimum [Member]
Lessee Lease Description [Line Items]
Remaining Term (years)	1 year
Other Leases [Member] | Maximum [Member]
Lessee Lease Description [Line Items]
Remaining Term (years)	3 years