Fair Value of Financial Instruments - Included in Notes Payable are the FHLB loan and Subordinated Debentures (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Document Period End Date	Mar. 31, 2020
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Interest rate (percent)	1.73%	1.73%
FHLB loan due and issued with fixed interest, Senior notes due and issued with fixed interest and Affiliate subordinated debentures due with variable interest	$ 21,500,000
Federal Home Loan Bank of Cincinnati [Member]
Debt Instrument [Line Items]
FHLB loan due and issued with fixed interest, Senior notes due and issued with fixed interest and Affiliate subordinated debentures due with variable interest	$ 85,000,000
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest rate (percent)	3.96%	3.96%
Affiliate Subordinated Debentures Due 2033 [Member]
Debt Instrument [Line Items]
Interest rate (percent)	5.78%	6.11%
FHLB loan due and issued with fixed interest, Senior notes due and issued with fixed interest and Affiliate subordinated debentures due with variable interest	$ 15,500,000.0
Reported Value Measurement [Member]
Debt Instrument [Line Items]
Total notes payable	182,100,000	$ 122,000,000.0
Reported Value Measurement [Member] | Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Total notes payable	21,600,000	21,500,000
Reported Value Measurement [Member] | Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Total notes payable	85,300,000	85,300,000
Reported Value Measurement [Member] | Affiliate Subordinated Debentures Due 2033 [Member]
Debt Instrument [Line Items]
Total notes payable	15,200,000	15,200,000
Estimate of Fair Value Measurement [Member]
Debt Instrument [Line Items]
Total notes payable	196,700,000	134,500,000
Estimate of Fair Value Measurement [Member] | Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Total notes payable	21,500,000	21,500,000
Estimate of Fair Value Measurement [Member] | Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Total notes payable	100,000,000.0	97,800,000
Estimate of Fair Value Measurement [Member] | Affiliate Subordinated Debentures Due 2033 [Member]
Debt Instrument [Line Items]
Total notes payable	$ 15,200,000	$ 15,200,000
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Interest rate (percent)	0.38%	0.00%
Federal Home Loan Bank Advances [Member] | Reported Value Measurement [Member]
Debt Instrument [Line Items]
Total notes payable	$ 60,000,000.0	$ 0
Federal Home Loan Bank Advances [Member] | Estimate of Fair Value Measurement [Member]
Debt Instrument [Line Items]
Total notes payable	$ 60,000,000.0	$ 0