Pension and Profit Sharing - Pension Plan Assets by Fair Value Hierarchy (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension plan assets	$ 1,028,649	$ 1,013,831	$ 1,249,825
Level 1
Pension plan assets	184,731	182,831
Level 2
Pension plan assets	843,918	831,000
Money Market Fund
Pension plan assets	16,794	17,324
Money Market Fund | Level 1
Pension plan assets	31	4
Money Market Fund | Level 2
Pension plan assets	16,763	17,320
Equity Common and Collected Funds
Pension plan assets	682,869	663,957
Equity Common and Collected Funds | Level 1
Pension plan assets	102,030	99,616
Equity Common and Collected Funds | Level 2
Pension plan assets	580,839	564,371
Fixed Income Common and Collected Funds
Pension plan assets	328,986	332,520
Fixed Income Common and Collected Funds | Level 1
Pension plan assets	82,670	83,211
Fixed Income Common and Collected Funds | Level 2
Pension plan assets	$ 246,316	$ 249,309