INCOME TAXES: Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Regulatory liabilities	$ 108,641	$ 94,946
Deferred compensation	24,288	24,495
Deferred revenue	58,860	53,418
Tax credits	52,010	44,727
Partnership investments	12,652	15,259
Retirement benefits	44,803	38,687
Other	26,537	19,657
Total	327,791	291,189
Deferred tax liabilities:
Property, plant and equipment	266,992	249,452
Regulatory assets	774,672	739,689
Deferred Tax Liabilities, Regulatory Assets	29,742	33,116
Partnership investments	3,593	3,355
Retirement benefits	94,231	80,777
Other	41,285	58,716
Total	1,210,515	1,165,105
Net deferred tax liabilities	882,724	873,916
Idaho Power Company
Deferred tax assets:
Regulatory liabilities	108,641	94,946
Deferred compensation	24,288	24,495
Deferred revenue	58,860	53,418
Tax credits	49,734	44,727
Partnership investments	12,652	15,259
Retirement benefits	44,803	38,687
Other	26,416	19,526
Total	325,394	291,058
Deferred tax liabilities:
Property, plant and equipment	266,992	249,452
Regulatory assets	774,672	739,689
Deferred Tax Liabilities, Regulatory Assets	29,742	33,116
Partnership investments	0	0
Retirement benefits	94,231	80,777
Other	40,807	58,716
Total	1,206,444	1,161,750
Net deferred tax liabilities	$ 881,050	$ 870,692

The amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of pension liabilities funded in advance and the basis of a prepaid pension asset determined in accordance with generally accepted accounting principles. The difference in basis of such costs will increase future taxable income when such basis difference reverses. Prepaid pension costs represented the cumulative employer's contributions in excess of net pension cost recognized, before the adoption of the recognition provisions of FAS 158. Under FAS 158, prepaid pension costs are no longer recognized in the statement of financial position.

No definition available.