LEASES - Maturities of Operating and Financing Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating Leases
2019	$ 58,853
2020	59,956
2021	61,158
2022	62,383
2023	63,201
After 2023	289,966
Total lease payments	595,517
Less: Interest	(216,444)
Present value of lease liabilities	379,073
2019		$ 58,291
2020		59,391
2021		60,575
2022		61,808
2023		63,065
After 2023		321,797
Total lease payments		624,927
Finance Leases
2019	375
2020	247
2021	222
2022	105
2023	39
After 2023	0
Total lease payments	988
Less: Interest	(79)
Present value of lease liabilities	909
2018		454
2019		174
2020		173
2021		127
2022		0
After 2022		0
Total lease payments		928
Operating and Finance Lease Liabilities, Payments, Due [Abstract]
2019	59,228	58,745
2020	60,203	59,565
2021	61,380	60,748
2022	62,488	61,935
2023	63,240	63,065
After 2023	289,966	321,797
Total lease payments	596,505	$ 625,855
Less: Interest	(216,523)
Present value of lease liabilities	$ 379,982