Employee Benefit Plans - 401(K) Saving And Retirement Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Benefit Plan Compensation
Compensation cost	$ 8,800	$ 7,400	$ 9,000
Non Employee Director
Employee Benefit Plan Compensation
Granted (in shares)	114,285	107,389	148,077
Compensation cost	$ 243	$ 261	$ 276
Savings And Retirement Plan 401 K
401(K) Savings & Retirement Plan
Percent of salary employee is permitted to contribute	100.00%
Vesting period	3 years
Common stock, shares issued	841,539	633,827
Total expense (including issuance of shares)	$ 1,900	$ 1,800	$ 1,600