Retirement Plans - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension plan termination expense	$ 9,526		$ 9,526
Recognition of pre-tax losses from pension plan		$ (7,700)
Write-off of pension plan asset		$ 1,800
Non-contributory defined benefit pension plan | Employees hired on or before December 31, 2005
Defined Benefit Plan Disclosure [Line Items]
Requisite age of employees for receiving retirement benefits under the plan		21 years
Non-contributory defined benefit pension plan | Employee hired on or after January 1, 2006
Defined Benefit Plan Disclosure [Line Items]
Requisite age of employees for receiving retirement benefits under the new benefit formula		45 years
Defined benefit plan requisite service period under new benefit formula		5 years