Federal Income Taxes - Narrative (Details) - USD ($)		12 Months Ended
	Dec. 23, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Income Tax Disclosure [Abstract]
Tax-effected change to the Provisional Change in Discounted Loss Reserves attributable to TCJA changes to loss reserve discounting		$ 700,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	21.00%	35.00%	35.00%
Corporate income tax rate due to enactment of TCJA		21.00%
Document Period End Date		Dec. 31, 2018
Impact of TCJA at enactment		$ 0	$ 43,500,000	$ 0
Pre-tax provisional change in discounted loss reserves attributable to TCJA			50,900,000		$ 47,500,000
Tax Adjustments, Settlements, and Unusual Provisions		1,600,000		$ 1,600,000
Deferred tax asset related to net operating loss carryforwards		15,100,000
Balance for uncertain tax positions		0
Interest and penalties payable		$ 0	$ 0