Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Oct. 01, 2018	Dec. 31, 2017
ASSETS:
Cash and cash equivalents	$ 2,509.0	$ 1,192.2			$ 13.3
Accounts receivable, net of allowance of $98.3 and $40.2, respectively	4,646.4	5,209.2			112.9
Accounts receivable, billable to clients	1,820.7	1,934.1			8.3
Assets held for sale	0.8	22.8
Other current assets	390.7	412.4			28.2
Total current assets	9,367.6	8,770.7
Property and equipment, net of accumulated depreciation of $1,133.9 and $1,116.4 respectively	690.3	778.1			159.7
Deferred income taxes	302.0	252.1
Goodwill	4,945.5	4,894.4		$ 4,875.9	1,110.8
Other intangible assets	933.6	1,014.3
Operating Lease, Right-of-Use Asset	1,379.3	1,574.4	$ 1,421.1
Other non-current assets	424.4	467.9			8.3
TOTAL ASSETS	18,042.7	17,751.9
LIABILITIES:
Accounts payable	7,269.7	7,205.4
Accrued liabilities	832.4	742.8
Contract liabilities	657.8	585.6			23.2
Short-term borrowings	48.0	52.4
Current portion of long-term debt	502.5	502.0
Operating Lease, Liability, Current	268.5	267.2
Liabilities held for sale	1.6	65.0
Total current liabilities	9,580.5	9,420.4
Long-term debt	2,915.8	2,771.9
Operating Lease, Liability, Noncurrent	1,441.0	1,429.6
Deferred compensation	413.2	425.0
Other non-current liabilities	655.2	714.7			$ 0.8
TOTAL LIABILITIES	15,005.7	14,761.6
Redeemable noncontrolling interests	93.1	164.7		167.9		$ 252.1
STOCKHOLDERS' EQUITY:
Common stock, $0.10 par value, shares authorized: 800.0 shares issued: 2020 - 390.9; 2019 - 387.0 shares outstanding: 2020 - 390.9; 2019 - 387.0	39.0	38.7
Additional paid-in capital	1,099.3	977.3
Retained earnings	2,636.9	2,689.9
Accumulated other comprehensive loss, net of tax	(880.2)	(930.0)		(941.1)
Total IPG stockholders' equity	2,895.0	2,775.9
Noncontrolling interests	48.9	49.7
TOTAL STOCKHOLDERS' EQUITY	2,943.9	2,825.6		$ 2,432.8		$ 2,246.3
TOTAL LIABILITIES AND EQUITY	$ 18,042.7	$ 17,751.9