Retirement Plans, Fair Value of Pension Plan Investments Table (Details) - RAP - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan Investments
RAP Investment Amount	$ 497,796	$ 478,849	$ 442,034
Fair Value, Inputs, Level 1
Pension Plan Investments
RAP Investment Amount	448,582	427,983
Fair Value, Inputs, Level 2
Pension Plan Investments
RAP Investment Amount	0	0
Fair Value, Inputs, Level 3
Pension Plan Investments
RAP Investment Amount	49,213	50,866
Money market account
Pension Plan Investments
RAP Investment Amount	5,446	9,429
Money market account | Fair Value, Inputs, Level 1
Pension Plan Investments
RAP Investment Amount	5,446	9,429
Money market account | Fair Value, Inputs, Level 2
Pension Plan Investments
RAP Investment Amount	0	0
Money market account | Fair Value, Inputs, Level 3
Pension Plan Investments
RAP Investment Amount	0	0
Common /collective trust funds
Pension Plan Investments
RAP Investment Amount	185,791	172,950
Common /collective trust funds | Fair Value, Inputs, Level 1
Pension Plan Investments
RAP Investment Amount	185,791	172,950
Common /collective trust funds | Fair Value, Inputs, Level 2
Pension Plan Investments
RAP Investment Amount	0	0
Common /collective trust funds | Fair Value, Inputs, Level 3
Pension Plan Investments
RAP Investment Amount	0	0
Mutual funds
Pension Plan Investments
RAP Investment Amount	257,345	245,605
Mutual funds | Fair Value, Inputs, Level 1
Pension Plan Investments
RAP Investment Amount	257,345	245,605
Mutual funds | Fair Value, Inputs, Level 2
Pension Plan Investments
RAP Investment Amount	0	0
Mutual funds | Fair Value, Inputs, Level 3
Pension Plan Investments
RAP Investment Amount	0	0
Group annuity contracts
Pension Plan Investments
RAP Investment Amount	49,213	50,866
Group annuity contracts | Fair Value, Inputs, Level 1
Pension Plan Investments
RAP Investment Amount	0	0
Group annuity contracts | Fair Value, Inputs, Level 2
Pension Plan Investments
RAP Investment Amount	0	0
Group annuity contracts | Fair Value, Inputs, Level 3
Pension Plan Investments
RAP Investment Amount	$ 49,213	$ 50,866