We are party to derivative contracts through certain of our subsidiaries. The most significant derivative contracts consist of equity index put option contracts. Information related to these contracts follows (dollars in millions).

	December 31,
	2020		2019
Balance sheet liabilities - at fair value	$	1,065	$	968
Notional value		10,991		14,385
Intrinsic value		727		397
Weighted average remaining life (in years)		1.2		1.8

The equity index put option contracts are European style options written prior to March 2008 on four major equity indexes. Notional value in the preceding table represents the aggregate undiscounted amounts payable assuming that the value of each index is zero at each contract’s expiration date. Intrinsic value is the undiscounted liability assuming the contracts are settled based on the index values and foreign currency exchange rates as of the balance sheet date. Substantially all open contracts as of December 31, 2020 will expire by February 2023.

Future payments, if any, under any given contract will be required if the prevailing index value is below the contract strike price at the expiration date. We received aggregate premiums of $1.9 billion on the contract inception dates with respect to unexpired contracts as of December 31, 2020 and we have no counterparty credit risk.

We recorded derivative contract losses of $159 million in 2020, gains of $1,484 million in 2019 and losses of $300 million in 2018, with respect to our equity index put option contracts. These gains and losses were primarily due to changes in the equity index values. These contracts may not be unilaterally terminated or fully settled before the expiration dates and the ultimate amount of cash basis gains or losses on these contracts will not be determined until the contract expiration dates.

Our regulated utility subsidiaries may use forward purchases and sales, futures, swaps and options to manage a portion of their commodity price risks. Most of these net derivative contract assets or liabilities of our regulated utilities are probable of recovery through rates and are offset by regulatory liabilities or assets.