we provide services under multi-year contracts that can restrict our ability to increase prices and the timing of such increases. As we entered 2022, many of these contract lookback provisions began to capture the inflationary cost increases experienced in the second half of 2021 in the price escalation calculation; however, due to the continued rapid pace of inflation as well as the relatively low inflationary cost environment of the first half of 2021, such timing lag persists.
Item 3. Quantitative and Qualitative Disclosures About Market Risk.
Information about market risks as of March 31, 2022 does not materially differ from the following information discussed under Item 7A in our Annual Report on Form 10-K for the year ended December 31, 2021:
In the normal course of business, we are exposed to market risks, including changes in interest rates, certain commodity prices and Canadian currency rates. From time to time, we use derivatives to manage some portion of these risks. The Company had no derivatives outstanding as of December 31, 2021.
Interest Rate Exposure — Our exposure to market risk for changes in interest rates relates primarily to our financing activities. As of December 31, 2021, we had $13.5 billion of long-term debt, excluding the impacts of accounting for debt issuance costs, discounts and fair value adjustments attributable to terminated interest rate derivatives. We had $2.5 billion of debt that is exposed to changes in market interest rates within the next 12 months comprised of (i) $1.8 billion of short-term borrowings under our commercial paper program; (ii) $645 million of tax-exempt bonds with term interest rate periods that expire within the next 12 months and (iii) $54 million of variable-rate tax-exempt bonds that are subject to repricing on a weekly basis. We currently estimate that a 100-basis point increase in the interest rates of our outstanding variable-rate debt obligations would increase our 2022 interest expense by $7 million.
Our remaining outstanding debt obligations have fixed interest rates through either the scheduled maturity of the debt or, for certain of our fixed-rate tax-exempt bonds, through the end of a term interest rate period that exceeds 12 months. The fair value of our fixed-rate debt obligations can increase or decrease significantly if market interest rates change.
We performed a sensitivity analysis to determine how market rate changes might affect the fair value of our market risk-sensitive debt instruments. This analysis is inherently limited because it reflects a singular, hypothetical set of assumptions. Actual market movements may vary significantly from our assumptions. An instantaneous, 100-basis point increase in interest rates across all maturities attributable to these instruments would have decreased the fair value of our debt by approximately $900 million as of December 31, 2021.
We are also exposed to interest rate market risk from our cash and cash equivalent balances, as well as assets held in restricted trust funds and escrow accounts. These assets are generally invested in high-quality, liquid instruments including money market funds that invest in U.S. government obligations with original maturities of three months or less. We believe that our exposure to changes in fair value of these assets due to interest rate fluctuations is insignificant as the fair value generally approximates our cost basis. We also invest a portion of our restricted trust and escrow account balances in available-for-sale securities, including U.S. Treasury securities, U.S. agency securities, municipal securities, mortgage- and asset-backed securities, which generally mature over the next nine years, as well as equity securities.
Commodity Price Exposure — In the normal course of our business, we are subject to operating agreements that expose us to market risks arising from changes in the prices for commodities such as diesel fuel, electricity and recycled materials, including old corrugated cardboard and plastics. We work to manage these risks through operational strategies that focus on capturing our costs in the prices we charge our customers for the services provided. Accordingly, as the market prices for these commodities increase or decrease, our revenues, operating costs and margins may also increase or decrease. We saw significant increases in commodity prices and demand for recycled materials in 2021, resulting in increased annual revenue for our recycling business of $537 million. Variability in commodity prices can also impact the margins of our business as certain components of our revenue are structured as a pass through of costs, including recycling brokerage and fuel surcharges.
Currency Rate Exposure — We have operations in Canada as well as certain support functions in India. Where significant, we have quantified and described the impact of foreign currency translation on components of income,