SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Effect of Accounting Standards Update (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Prepaid expenses	$ 80,353	$ 21,840
Property, plant and equipment, net	965,901	713,274
Operating lease right-of-use assets	143,782	0
Liabilities
Other current liabilities	228,277	151,753
Other long-term liabilities	$ 183,096	39,139
Cumulative Effect, Period of Adoption, Adjustment
ASSETS
Prepaid expenses		(180)
Property, plant and equipment, net		3,237
Operating lease right-of-use assets		90,932
Liabilities
Other current liabilities		8,030
Other long-term liabilities		86,152
Cumulative Effect, Period of Adoption, Adjusted Balance
ASSETS
Prepaid expenses		21,660
Property, plant and equipment, net		716,511
Operating lease right-of-use assets		90,932
Liabilities
Other current liabilities		159,783
Other long-term liabilities		$ 125,291