Benefit Plans, Other Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Plans [Abstract]
Employer contribution matching, first 4% of employee contribution	100.00%
Employer contribution percent of employee contribution, 100% matching	4.00%
Employer matching contribution	$ 5,173	$ 4,770	$ 3,932