Employee Benefit Plans - Summary of Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Loss (Details) - Pension and Post-retirement Plan - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Components of Net Periodic Benefit Cost
Service cost	$ 200,000	$ 700,000	$ 600,000	$ 1,800,000
Interest cost	1,700,000	2,100,000	5,200,000	6,300,000
Expected return on plan assets	(1,700,000)	(1,800,000)	(5,100,000)	(5,400,000)
Amortization of net loss	800,000	900,000	2,000,000.0	2,900,000
Amortization of prior service credit	0	(100,000)	0	(400,000)
Net periodic benefit cost	1,000,000.0	$ 1,800,000	2,700,000	$ 5,200,000
Employer contributions			0
Expected contributions to be made in current year	$ 0		$ 0