INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Developer deposits for contributions in aid of construction	$ 33,244	$ 31,589
Net operating loss carry-forward and tax credits	29,406	18,329
Pension liability	16,896	13,860
Income tax regulatory liability	18,364	22,838
Operating leases liabilities	3,796	4,170
Other	3,614	4,264
Total deferred tax assets	105,320	95,050
Deferred tax liabilities:
Property related basis and depreciation differences	437,224	393,007
WRAM/MCBA and interim rates balancing accounts	4,875	14,192
Operating lease-right to use asset	3,746	4,130
Other	12,237	13,972
Total deferred tax liabilities	458,082	425,301
Net deferred tax liabilities	$ 352,762	$ 330,251