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 to the financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2018. During the six months ended March 31, 2019, there were no changes in these methods.

Fair value measurements also apply to the valuation of our pension and postretirement plan assets. Current accounting guidance requires employers to annually disclose information about fair value measurements of the assets of a defined benefit pension or other postretirement plan. The fair value of these assets is presented in Note 7 to the financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2018.

Quantitative Disclosures

Financial Instruments

The classification of our fair value measurements requires judgment regarding the degree to which market data is observable or corroborated by observable market data. Authoritative accounting literature establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1), with the lowest priority given to unobservable inputs (Level 3). 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 March 31, 2019 and September 30, 2018. 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		March 31, 2019
	(In thousands)
Assets:
Financial instruments	$	—	$	1,611	$	—	$	—	$	1,611
Debt and equity securities
Registered investment companies	42,412		—		—		—		42,412
Bond mutual funds	21,935		—		—		—		21,935
Bonds⁽²⁾	—		29,890		—		—		29,890
Money market funds	—		2,440		—		—		2,440
Total debt and equity securities	64,347		32,330		—		—		96,677
Total assets	$	64,347	$	33,941	$	—	$	—	$	98,288
Liabilities:
Financial instruments	$	—	$	38	$	—	$	—	$	38



	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
Debt and equity securities
Registered investment companies	42,644		—		—		—		42,644
Bond mutual funds	21,507		—		—		—		21,507
Bonds⁽²⁾	—		31,400		—		—		31,400
Money market funds	—		3,834		—		—		3,834
Total debt and equity securities	64,151		35,234		—		—		99,385
Total assets	$	64,151	$	36,853	$	—	$	—	$	101,004
Liabilities:
Financial instruments	$	—	$	56,837	$	—	$	—	$	56,837

(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 that are valued at cost.


(2)	Our investments in bonds are considered available-for-sale debt securities in accordance with current accounting guidance as described in Note 2.

Debt and equity securities are comprised of our available-for-sale debt securities and our equity securities. We regularly evaluate the performance of our available-for-sale debt securities on an investment by investment basis for impairment, taking into consideration the investment’s purpose, volatility and current returns. If a determination is made that a decline in fair value is other than temporary, the related investment is written down to its estimated fair value and the other-than-temporary impairment is recognized in the statement of comprehensive income. At March 31, 2019 and September 30, 2018, our available-for-sale debt securities amortized cost was $29.9 million and $31.5 million. At March 31, 2019, we maintained investments in bonds that have contractual maturity dates ranging from April 2019 through February 2022.

Other Fair Value Measures

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 March 31, 2019 and September 30, 2018:



	March 31, 2019		September 30, 2018
	(In thousands)
Carrying Amount	$	3,685,000	$	3,085,000
Fair Value	$	3,965,641	$	3,161,679