Retirement Plans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension plan termination expense		$ 9.5
Recognition of pre-tax losses from pension plan	$ (7.7)
Write-off of pension plan asset	$ 1.8
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