Leases - Lease Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Leases
Operating Lease Right-of-use assets	$ 84,646	$ 87,167	$ 87,200
Operating Lease, Short-term lease liability	15,700		16,800
Operating Lease Long-term lease liability	$ 78,616	80,568	$ 80,600
Operating Lease Weighted average remaining lease term	7 years 4 months 24 days		7 years 7 months 6 days
Operating Lease Weighted average discount rate	3.00%		3.00%
Finance Lease, Right-of-use assets	$ 13,200	500
Finance Lease, short-term lease liability	2,800	200
Finance Lease, Long-term lease liability	$ 10,386	$ 395
Finance Lease, Weighted average remaining lease term	4 years 10 months 24 days	2 years 4 months 24 days
Finance Lease, Weighted average discount rate	1.75%	1.70%