NOTE 5 — FAIR VALUE MEASUREMENTS

Financial instruments recorded in the balance sheet include cash and cash equivalents, trade accounts receivable, marketable securities, notes and accounts payable, and debt.

An allowance for anticipated uncollectible trade receivable amounts is established using a combination of specifically identified accounts to be reserved, and a reserve covering trends in collectibility. These estimates are based on an analysis of trends in collectibility and past experience, but are primarily made up of individual account balances identified as doubtful based on specific facts and conditions. Receivable losses are charged against the allowance when we confirm uncollectibility.

The valuation techniques utilized for establishing the fair values of assets and liabilities are based on observable and unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, while unobservable inputs reflect management’s market assumptions. The fair value hierarchy has three levels based on the reliability of the inputs used to determine fair value, as follows:

Level 1 Inputs — Quoted prices for identical instruments in active markets.

Level 2 Inputs — Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable.

Level 3 Inputs — Instruments with primarily unobservable value drivers.

The following tables present our assets and liabilities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy.

(In thousands)	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Fair Value at February 28, 2018
U.S. Treasury and other government	$	-	$	22,209	$	-		$	22,209
Corporate bonds				574					574
Stocks - domestic		1,311							1,311
Mutual funds - foreign				48,327					48,327
Mutual funds - domestic				105,379					105,379
Contingent consideration						(14,653	)		(14,653	)
Total	$	1,311	$	176,489	$	(14,653	)	$	163,147

(In thousands)	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Fair Value at May 31, 2017
U.S. Treasury and other government	$	-	$	22,119	$	-		$	22,119
Corporate bonds				797					797
Stocks - domestic		2,467							2,467
Mutual funds - foreign				37,435					37,435
Mutual funds - domestic				101,637					101,637
Contingent consideration						(17,979	)		(17,979	)
Total	$	2,467	$	161,988	$	(17,979	)	$	146,476

Our marketable securities are primarily composed of available-for-sale securities, and are valued using a market approach. The availability of inputs observable in the market varies from instrument to instrument and depends on a variety of factors including the type of instrument, whether the instrument is actively traded, and other characteristics particular to the transaction. For most of our financial instruments, pricing inputs are readily observable in the market, the valuation methodology used is widely accepted by market participants, and the valuation does not require significant management discretion. For other financial instruments, pricing inputs are less observable in the market and may require management judgment.

The contingent consideration represents the estimated fair value of the additional variable cash consideration payable in connection with recent acquisitions that is contingent upon the achievement of certain performance milestones. We estimated the fair value using expected future cash flows over the period in which the obligation is expected to be settled, and applied a discount rate that appropriately captures a market participant's view of the risk associated with the obligation, which are considered to be Level 3 inputs. During the first nine months of fiscal 2018, we paid approximately $3.8 million for settlements of contingent consideration obligations relating to certain performance milestones that were established in prior periods and achieved during the current period, and we increased our accrual by $0.5 million for fair value adjustments. During the first nine months of fiscal 2017, we accrued an additional approximate $6.9 million for contingent payments related to acquisitions, including the estimated amount for the mandatory purchase of a step-acquisition, and paid approximately $4.2 million for settlements of contingent consideration obligations relating to certain performance milestones that were established in prior periods and achieved during last year’s first nine months. These amounts are reported in payments of acquisition-related contingent consideration in cash flows from financing activities in the Consolidated Statements of Cash Flows.

The carrying value of our current financial instruments, which include cash and cash equivalents, marketable securities, trade accounts receivable, accounts payable and short-term debt approximates fair value because of the short-term maturity of these financial instruments. At February 28, 2018 and May 31, 2017, the fair value of our long-term debt was estimated using active market quotes, based on our current incremental borrowing rates for similar types of borrowing arrangements, which are considered to be Level 2 inputs. Based on the analysis performed, the fair value and the carrying value of our financial instruments and long-term debt as of February 28, 2018 and May 31, 2017 are as follows:

	At February 28, 2018
(In thousands)	Carrying Value		Fair Value
Cash and cash equivalents	$	264,386	$	264,386
Marketable equity securities		155,017		155,017
Marketable debt securities		22,783		22,783
Long-term debt, including current portion		2,183,425		2,243,062

	At May 31, 2017
(In thousands)	Carrying Value		Fair Value
Cash and cash equivalents	$	350,497	$	350,497
Marketable equity securities		141,539		141,539
Marketable debt securities		22,916		22,916
Long-term debt, including current portion		2,090,082		2,243,167