11) Retirement Plans: Noncontributory Employee Stock Ownership Plan (ESOP) (Details) - Employee Stock Ownership Plan ESOP	12 Months Ended
	Dec. 31, 2019 shares
Employee Stock Ownership Plan (ESOP), Plan Description	The Company and its subsidiaries have a noncontributory Employee Stock Ownership Plan (“ESOP”) for all eligible employees. Eligible employees are primarily those with more than one year of service, who work in excess of 1,000 hours per year. Contributions, which may be in cash or stock of the Company, are determined annually by the Board of Directors.
Common Class A
Employee Stock Ownership Plan (ESOP), Shares in ESOP	495,618
Common Class C
Employee Stock Ownership Plan (ESOP), Shares in ESOP	307,491