Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2021

The estimated fair value of financial instruments at March 31, 2021 was as follows:


			Fair Value Measurements at Reporting Date Using
(In millions)	Total Carrying Amount		Total Estimated Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)
Cash and cash equivalents	$	541.7	$	541.7	$	541.7	$	—
Derivative financial instruments:
Assets	3.2		3.2		—		3.2
Liabilities	3.7		3.7		—		3.7
Debt (a)	1,629.2		1,938.4		1,684.8		253.6

The estimated fair value of financial instruments at December 31, 2020 was as follows:


			Fair Value Measurements at Reporting Date Using
(In millions)	Total Carrying Amount		Total Estimated Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)
Cash and cash equivalents	$	645.9	$	645.9	$	645.9	$	—
Derivative financial instruments:
Assets	4.8		4.8		—		4.8
Liabilities	4.0		4.0		—		4.0
Debt (a)	1,629.1		1,847.7		1,594.2		253.5

(a)The total carrying amount for debt for both periods excludes debt issuance costs related to the recognized debt liability which is presented in the consolidated balance sheet as a direct reduction from the carrying amount of the debt liability. The December 31, 2020 debt carrying value includes $46.8 million for the unamortized balance of the portion of the 2025 Convertible Notes recorded in stockholders’ equity due to the flexible settlement feature of the notes. Effective January 1, 2021, ATI early-adopted new accounting guidance that eliminated the equity component classification of the embedded conversion option of the 2025 Convertible Notes (see Note 1).