Multiemployer Defined Benefit Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Jun. 30, 2017
Multiemployer Defined Benefit Plan Funded Status	85.94%	88.12%
Entity Tax Identification Number	13-5645888
Multiemployer Plan Number	333
Multiemployer Plans, Plan Contributions			$ 164,570,408	$ 367,119,418
Description of Defined benefit Plan Employers Contribution to Total Contribution	not more than 5% of the total contributions to the Pentegra DB Plan
Accounting Standards Update 2011-09 [Member]
Description of Defined benefit Plan Employers Contribution to Total Contribution	if an employer's contributions represent more than 5% of total contributions to the Pentegra DB Plan
Cincinnati Federal [Member]
Multiemployer Plan, Contributions by Employer	$ 105,511	$ 145,930