Leases - Maturities of Operating and Finance Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating Leases
2019 (remainder of year)	$ 67,567
2020	250,778
2021	213,486
2022	173,399
2023	131,550
Thereafter	556,103
Total undiscounted cash flows	1,392,883
Less: Imputed interest	351,742
Total operating lease liabilities	1,041,141
Finance Leases
2019 (remainder of year)	294
2020	1,182
2021	1,193
2022	1,203
2023	1,214
Thereafter	31,630
Total undiscounted cash flows	36,716
Less: Imputed interest	23,369
Total finance lease liabilities	13,347
Total
2019 (remainder of year)	67,861
2020	251,960
2021	214,679
2022	174,602
2023	132,764
Thereafter	587,733
Total undiscounted cash flows	1,429,599
Less: Imputed interest	375,111
Total operating lease liabilities	$ 1,054,488
Operating Leases
2019		$ 267,846
2020		231,711
2021		193,155
2022		150,155
2023		107,759
Thereafter		484,038
Total		$ 1,434,664