Liability for Unpaid Claims and Claim Adjustment Expenses - Summary of Incurred and Paid Claims Development as Supplementary Information - Credit Life (Detail) $ in Thousands	Dec. 31, 2019 USD ($) claim	Dec. 31, 2018 USD ($)
Claims Development [Line Items]
Liabilities for claims and claim adjustment expenses, net of reinsurance	$ 995,986
Credit Life
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	12,154
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance	10,962
All outstanding liabilities before period one, net of reinsurance	0
Liabilities for claims and claim adjustment expenses, net of reinsurance	1,192
Credit Life | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	6,198	$ 5,849
IBNR plus expected development	$ 8
Cumulative number of reported claims | claim	8,000
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance	$ 6,190	$ 4,795
Credit Life | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	5,956
IBNR plus expected development	$ 1,155
Cumulative number of reported claims | claim	16,000
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance	$ 4,772