Employee Benefit Plans Employee Benefit Plans 7 (Details) - Pension Benefits - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee benefit plans
Fair Value	$ 192,477	$ 162,529	$ 173,648
Unfunded Commitments	0	0
Cash equivalents
Employee benefit plans
Fair Value	600	590
Unfunded Commitments	0	0
Fixed income fund
Employee benefit plans
Fair Value	74,123	70,642
Unfunded Commitments	0	0
U.S. small/mid cap funds
Employee benefit plans
Fair Value	17,865	22,313
Unfunded Commitments	0	0
U.S. large cap funds
Employee benefit plans
Fair Value	47,132	46,133
Unfunded Commitments	0	0
International funds
Employee benefit plans
Fair Value	43,778	15,548
Unfunded Commitments	0	0
Total equity funds
Employee benefit plans
Fair Value	108,775	83,994
Unfunded Commitments	0
Real estate funds
Employee benefit plans
Fair Value	8,979	7,303
Unfunded Commitments	$ 0	$ 0