Nonqualified Benefit Plans Defined Contribution (Details 5) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan
Defined Benefit Plan Disclosure [Line Items]
Nonqualified Defined Contribution Plan, Cost	$ 51,800,000	$ 42,400,000	$ 41,200,000
Nonqualified Plan | Unfunded Plan
Defined Benefit Plan Disclosure [Line Items]
Nonqualified Defined Contribution Plan, Cost	$ 1,600,000	$ 597,000	$ 736,000