Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Benefit Plans
Employer matching contribution, percent matched	100.00%	100.00%	100.00%
Percentage of employees gross pay that is matched	6.00%	6.00%	6.00%
Matching contribution to the plan	$ 1,340,000	$ 1,505,000	$ 1,480,000