Fair Value Measurements

We report certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We record cash and cash equivalents, accounts receivable and accounts payable at carrying value, which substantially approximates fair value due to the short-term nature of these assets and liabilities. For other financial assets and liabilities, we primarily use quoted market prices and other observable market pricing information to minimize the use of unobservable pricing inputs in our measurements when determining fair value. The methods used to determine fair value for our assets and liabilities are fully described in Note 2.

Fair value measurements also apply to the valuation of our pension and post-retirement plan assets. The fair value of these assets is presented in Note 7.

Quantitative Disclosures

Financial Instruments

The classification of our fair value measurements requires judgment regarding the degree to which market data are observable or corroborated by observable market data. The following tables summarize, by level within the fair value hierarchy, our assets and liabilities that were accounted for at fair value on a recurring basis as of September 30, 2018 and 2017. As required under authoritative accounting literature, assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement.



	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)⁽¹⁾		Significant Other Unobservable Inputs (Level 3)		Netting and Cash Collateral		September 30, 2018
	(In thousands)
Assets:
Financial instruments	$	—	$	1,619	$	—	$	—	$	1,619
Available-for-sale securities
Registered investment companies	42,644		—		—		—		42,644
Bond mutual funds	21,507		—		—		—		21,507
Bonds	—		31,400		—		—		31,400
Money market funds	—		3,834		—		—		3,834
Total available-for-sale securities	64,151		35,234		—		—		99,385
Total assets	$	64,151	$	36,853	$	—	$	—	$	101,004
Liabilities:
Financial instruments	$	—	$	56,837	$	—	$	—	$	56,837



	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)⁽¹⁾		Significant Other Unobservable Inputs (Level 3)		Netting and Cash Collateral		September 30, 2017
	(In thousands)
Assets:
Financial instruments	$	—	$	3,239	$	—	$	—	$	3,239
Available-for-sale securities
Registered investment companies	41,097		—		—		—		41,097
Bond mutual funds	16,371		—		—		—		16,371
Bonds	—		29,104		—		—		29,104
Money market funds	—		1,837		—		—		1,837
Total available-for-sale securities	57,468		30,941		—		—		88,409
Total assets	$	57,468	$	34,180	$	—	$	—	$	91,648
Liabilities:
Financial instruments	$	—	$	112,398	$	—	$	—	$	112,398

(1)

Our Level 2 measurements consist of over-the-counter options and swaps, which are valued using a market-based approach in which observable market prices are adjusted for criteria specific to each instrument, such as the strike price, notional amount or basis differences, municipal and corporate bonds, which are valued based on the most recent available quoted market prices and money market funds which are valued at cost.

Available-for-sale securities, which include debt and equity securities, are comprised of the following:



	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
	(In thousands)
As of September 30, 2018
Domestic equity mutual funds	$	26,950	$	9,363	$	(353	)	$	35,960
Foreign equity mutual funds	4,656		2,028		—			6,684
Bond mutual funds	21,810		—		(303		)	21,507
Bonds	31,511		13		(124		)	31,400
Money market funds	3,834		—		—			3,834
	$	88,761	$	11,404	$	(780	)	$	99,385
As of September 30, 2017
Domestic equity mutual funds	$	25,361	$	8,920	$	—		$	34,281
Foreign equity mutual funds	4,581		2,235		—			6,816
Bond mutual funds	16,391		2		(22		)	16,371
Bonds	29,074		46		(16		)	29,104
Money market funds	1,837		—		—			1,837
	$	77,244	$	11,203	$	(38	)	$	88,409

At September 30, 2018 and 2017, our available-for-sale securities included $46.5 million and $42.9 million related to assets held in separate rabbi trusts for our supplemental executive retirement plans as discussed in Note 7. At September 30, 2018 we maintained investments in bonds that have contractual maturity dates ranging from October 2018 through September 2021.

Other Fair Value Measures

In addition to the financial instruments above, we have several financial and nonfinancial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, accounts payable and debt. The nonfinancial assets and liabilities include asset retirement obligations and pension and post-retirement plan assets. We record cash and cash equivalents, accounts receivable, accounts payable and debt at carrying value. For cash and cash equivalents, accounts receivable and accounts payable, we consider carrying value to materially approximate fair value due to the short-term nature of these assets and liabilities.

Our debt is recorded at carrying value. The fair value of our debt is determined using third party market value quotations, which are considered Level 1 fair value measurements for debt instruments with a recent, observable trade or Level 2 fair value measurements for debt instruments where fair value is determined using the most recent available quoted market price. The following table presents the carrying value and fair value of our debt as of September 30, 2018:



	September 30, 2018
	(In thousands)
Carrying Amount	$	3,085,000
Fair Value	$	3,161,679