Leases (Schedule of Maturity of Lease Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Operating Leases
2020		$ 103,106
2021	$ 135,875
2022			$ 116,818
2023			114,990
2024			110,652
Remaining	478,780
Total future minimum lease payments	1,060,221
Less imputed interest	(247,935)
Present value of lease liabilities	812,286
Finance Leases
2020	801
2021			1,069
2022	1,069
2023	1,069
2024			1,069
Remaining			4,541
Total future minimum lease payments	9,618
Less imputed interest	(1,842)
Present value of lease liabilities	7,776
Total
2020			$ 103,907
2021	136,944
2022	117,887
2023	116,059
2024	111,721
Remaining	483,321
Total future minimum lease payments	1,069,839
Less imputed interest	(249,777)
Present value of lease liabilities	820,062
Minimum lease payments for leases signed but not yet commenced	$ 256,700
Lease duration for leases signed but not yet commenced		20 years