Equifax Inc. Annual report pursuant to Section 13 and 15(d)

ACQUISITIONS AND INVESTMENTS (Additional Information) (Details)

v3.8.0.1

ACQUISITIONS AND INVESTMENTS (Additional Information) (Details) AUD / shares in Units, AUD in Millions				12 Months Ended
	May 16, 2016	Feb. 24, 2016 USD ($)	Feb. 24, 2016 AUD	Dec. 31, 2017 USD ($)	Nov. 15, 2017	Aug. 10, 2017	Dec. 31, 2016 USD ($)	Aug. 23, 2016	Feb. 24, 2016 AUD AUD / shares
Business Acquisition [Line Items]
Long-term debt				$ 2,715,300,000			$ 2,685,400,000
Bridge loan, term	364 days	364 days	364 days
364 Day Revolver
Business Acquisition [Line Items]
Debt instrument, face amount		$ 800,000,000
Bridge loan, term	364 days			364 days
Term loan, due Nov 2018
Business Acquisition [Line Items]
Long-term debt				$ 400,000,000			$ 450,000,000
Debt instrument, face amount		$ 800,000,000
Debt instrument, term		3 years	3 years
ID Watchdog, Inc.
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired						100.00%
Mercury Group Of Companies Pty Ltd
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired					100.00%
Veda
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired		100.00%							100.00%
Business combination, consideration transferred		$ 1,700,000,000	AUD 2,400.0
Business combination, separately recognized transactions, liabilities recognized		189,500,000							AUD 261.9
Business acquisition, share price (in Australian dollars per share) \| AUD / shares									AUD 2.825
Long-term debt		$ 1,700,000,000
Barnett and Computersoft
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired								100.00%

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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The amount of liabilities recognized recorded in a transaction with the acquiree for each transaction that is recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.

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Face (par) amount of debt instrument at time of issuance.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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