Our liabilities consist mainly of fixed and variable rate debt, denominated in U.S. dollars and various other currencies, which we issue in the global capital markets, while our assets consist primarily of U.S. dollar denominated, fixed rate receivables. We enter into interest rate swaps, and foreign currency swaps to economically hedge the interest rate and foreign currency risks that result from the different characteristics of our assets and liabilities. Our use of derivative transactions is intended to reduce long-term fluctuations in the fair value of assets and liabilities caused by market movements. All of our derivative activities are authorized and monitored by our management and our Asset-Liability Committee which provides a framework for financial controls and governance to manage market risk.

Accounting guidance permits the net presentation on our Consolidated Balance Sheets of derivative receivables and derivative payables with the same counterparty and the related cash collateral when a legally enforceable master netting agreement exists. When we meet this condition, we elect to present such balances on a net basis.

Our International Swaps and Derivatives Association (“ISDA”) Master Agreements are our master netting agreements which permit multiple transactions to be cancelled and settled with a single net balance paid to either party. The master netting agreements also contain reciprocal collateral agreements which require the transfer of cash collateral to the party in a net asset position across all transactions. Our collateral agreements with substantially all our counterparties include a zero threshold, full collateralization arrangement. Although we have daily valuation and collateral exchange arrangements with all of our counterparties, due to the time required to move collateral, there may be a delay of up to one day between the exchange of collateral and the valuation of our derivatives. We would not be required to post additional collateral to the counterparties with whom we were in a net liability position at September 30, 2020 if our credit ratings were to decline, since we fully collateralize without regard to credit ratings with these counterparties. In addition, as our collateral agreements include legal right of offset provisions, collateral amounts are netted against derivative assets or derivative liabilities, the net amount of which is included in Other assets or Other liabilities in our Consolidated Balance Sheets.

The following tables show the financial statement line item and amount of our derivative assets and liabilities that are reported in our Consolidated Balance Sheets:

	September 30, 2020					March 31, 2020
			Fair					Fair
	Notional		value			Notional		value
Other assets:
Interest rate swaps	$	35,879	$	1,387		$	30,362	$	1,410
Foreign currency swaps		5,926		260			488		27
Total	$	41,805	$	1,647		$	30,850	$	1,437

Counterparty netting				(850	)				(966	)
Collateral held				(731	)				(420	)
Carrying value of derivative contracts – Other assets			$	66				$	51

Other liabilities:
Interest rate swaps	$	56,816	$	1,605		$	69,079	$	1,826
Foreign currency swaps		6,168		306			13,181		1,290
Total	$	62,984	$	1,911		$	82,260	$	3,116

Counterparty netting				(850	)				(966	)
Collateral posted				(1,055	)				(2,105	)
Carrying value of derivative contracts – Other liabilities			$	6				$	45

As of September 30, 2020 and March 31, 2020, we held excess collateral of $10 million, respectively, which we did not use to offset derivative assets and was recorded in Other liabilities in our Consolidated Balance Sheets. As of September 30, 2020 and March 31, 2020, we posted excess collateral of $11 million and $1 million, respectively, which we did not use to offset derivative liabilities and was recorded in Other assets in our Consolidated Balance Sheets.

The following table summarizes the components of interest expense, including the location and amount of gains and losses on derivative instruments and related hedged items, as reported in our Consolidated Statements of Income:

	Three months ended						Six months ended
	September 30,						September 30,
	2020			2019			2020			2019
Interest expense on debt	$	495		$	639		$	1,071		$	1,294
Interest expense on derivatives		122			37			231			49
Interest expense on debt and derivatives		617			676			1,302			1,343

Losses (gains) on debt denominated in foreign currencies		500			(475	)		1,048			(460	)
(Gains) losses on foreign currency swaps		(503	)		474			(1,096	)		366
(Gains) losses on U.S. dollar interest rate swaps		(119	)		(62	)		(211	)		61
Total interest expense	$	495		$	613		$	1,043		$	1,310

Interest expense on debt and derivatives represents net interest settlements and changes in accruals. Gains and losses on derivatives and debt denominated in foreign currencies exclude net interest settlements and changes in accruals. Cash flows associated with derivatives are reported in Net cash provided by operating activities in our Consolidated Statements of Cash Flows.