LEASES - Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Remainder of 2019	$ 12,709
2020	21,558
2021	21,366
2022	21,989
2023	17,877
Later years	70,056
Discount	(32,298)
Total discounted operating lease liabilities	$ 133,257	$ 144,000	$ 0
2019			28,240
2020			25,331
2021			27,025
2022			28,012
2023			23,801
Later years			118,497
Total discounted operating lease liabilities			$ 250,906