Fair value is defined as the price that would be received for an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. The fair value accounting guidance provides a three-level hierarchy for classifying financial instruments. The levels of inputs used to determine the fair value of our financial assets and liabilities carried on the balance sheet at fair value and for those which only disclosure of fair value is required are characterized in accordance with the fair value hierarchy established by ASC 820, Fair Value Measurements. Where inputs for a financial asset or liability fall in more than one level in the fair value hierarchy, the financial asset or liability is classified in its entirety based on the lowest level input that is significant to the fair value measurement of that financial asset or liability. We use our judgment and consider factors specific to the financial assets and liabilities in determining the significance of an input to the fair value measurements. As of March 31, 2015 and December 31, 2014, only our residual assets (described in Note 5), financing receivables held-for-sale and investments available-for-sale, if any, were carried at fair value on the condensed consolidated balance sheets on a recurring basis. The three levels of the fair value hierarchy are described below:

Unless otherwise discussed below, fair value is measured using a discounted cash flow model, contractual terms and Level 3 unobservable inputs which consist of base interest rates and spreads over base rates which are based upon market observation and recent comparable transactions. An increase in these unobservable inputs would result in a lower fair value and a decline would result in a higher fair value.

Financing Receivables and Investments

The fair value of financing receivables and investments is measured using a discounted cash flow model, contractual terms and Level 3 unobservable inputs. For investments held at fair value, we used a range of interest rate spreads of 2% to 5% based upon comparable transactions. The financing receivables held for sale are carried at cost, which approximates fair value.

During 2014 as part of our portfolio management process, we sold an investment designated as held-to-maturity. As a result, we have transferred all of our remaining investments in debt securities to investments available-for-sale at fair value. The following table reconciles the beginning and ending balances for our Level 3 investments that are carried at fair value following the transfer of our investments to available-for-sale:

Non-recurring Fair Value Measurements

Our financial statements may include non-recurring fair value measurements related to acquisitions, if any. Assets acquired in a business combination are recorded at their fair value. We use third party valuation firms to assist us with developing our estimates of fair value. These valuations are prepared using Level 3 inputs.

Concentration of Credit Risk

Financial instruments that potentially subject us to concentrations of credit risk are principally cash and cash equivalents. As of March 31, 2015 and December 31, 2014, we had cash deposits held in U.S. banks of $80 million and $70 million, respectively. Included in these balances are $77 million and $66 million in bank deposits, respectively, in excess of amounts federally insured.

Financing receivables, investments and leases consist of primarily U.S. federal government-backed receivables, investment grade state and local government receivables and receivables from various sustainable infrastructure projects and do not, in our view, represent a significant concentration of credit risk. See Note 6 for an analysis by type of obligor.