Employee Benefit Plans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Contribution	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Executive Retirement Plan, Life Insurance Arrangements and Senior Management Retention Plan [Abstract]
Tax-exempt interest earned on the life insurance policies	$ 1,900	$ 1,822	$ 1,864
Executive Officers [Member]
Executive Retirement Plan, Life Insurance Arrangements and Senior Management Retention Plan [Abstract]
Employer contribution	6,200	4,300	3,800
Total accrued liability	48,500	43,300
Tax-exempt interest earned on the life insurance policies	1,900	1,800	1,900
Cash surrender value of life insurance policies	65,100	59,600
Senior Level Employees [Member] | Senior Management Retention Plan [Member]
Executive Retirement Plan, Life Insurance Arrangements and Senior Management Retention Plan [Abstract]
Employer contribution	1,500	765	627
Total accrued liability	$ 5,700	4,400
Profit Sharing Plan [Member]
Profit Sharing Plan [Abstract]
us-gaap_PensionPlansDefinedBenefitMember	us-gaap:DefinedContributionPlanTypeExtensibleList
Minimum requisite service period	1 year
Number of annual employer contribution | Contribution	2
Employer discretionary contribution amount	$ 1,200	1,000	975
Employer mandatory contributions amount	$ 1,400	$ 1,200	$ 1,200
Annual vesting percentage, first year	0.00%
Annual vesting percentage, full year thereafter	25.00%
Benefit vesting period	5 years