Employer Sponsored Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Service cost	$ 136	$ 46	$ 0
Interest cost	2,886	2,595	2,058
Expected return on plan assets	(2,601)	(3,339)	(2,376)
Amortization of actuarial net loss	464	1,024	1,092
Total net periodic benefit cost	885	326	774
Settlement loss	25,247	0	0
Total employer pension plan cost	$ 26,132	$ 326	$ 774