Employee Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Definedcontributionemployeeautomaticcontributionpercentag	6.00%
Administrative expenses	$ 0	$ 0	$ 0
Contributions made to the defined contribution plan	$ 7,000,000.0	8,100,000	6,100,000
Profits sharing, percent of pre-tax profit paid to eligible employees on quarterly basis	10.00%
Employee profit sharing bonus plan	$ 7,400,000	6,200,000	8,400,000
Medical claim payments	5,900,000	5,900,000	4,800,000
Heath saving account payments	$ 3,300,000	$ 2,900,000	$ 2,500,000
Effective January 1, 2016
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	175.00%
Maximum annual contributions per employee, percent	6.00%