Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
REVENUE:
Net revenue	$ 1,954.6	$ 2,061.4	$ 5,780.1	$ 6,192.1
Billable expenses	170.9	376.7	730.9	1,127.4
Total revenue	2,125.5	2,438.1	6,511.0	7,319.5
OPERATING EXPENSES:
Salaries and related expenses	1,269.9	1,334.4	3,998.8	4,136.7
Office and other direct expenses	307.9	367.9	1,003.1	1,144.4
Billable expenses	170.9	376.7	730.9	1,127.4
Cost of services	1,748.7	2,079.0	5,732.8	6,408.5
Selling, general and administrative expenses	9.9	9.8	36.4	69.3
Depreciation and amortization	71.0	69.0	216.9	213.1
Restructuring charges	47.3	0.0	159.9	33.9
Total operating expenses	1,876.9	2,157.8	6,146.0	6,724.8
OPERATING INCOME	248.6	280.3	365.0	594.7
EXPENSES AND OTHER INCOME:
Interest expense	(50.8)	(49.7)	(145.4)	(151.1)
Interest income	6.1	9.5	22.7	25.0
Other Nonoperating Income (Expense)	(11.3)	(7.4)	(54.6)	(18.1)
Total (expenses) and other income	(56.0)	(47.6)	(177.3)	(144.2)
Income before income taxes	192.6	232.7	187.7	450.5
Provision for income taxes	(86.3)	64.6	(50.1)	118.7
Income of consolidated companies	278.9	168.1	237.8	331.8
Equity in net income (loss) of unconsolidated affiliates	(0.4)	0.3	(0.6)	(0.1)
NET INCOME	278.5	168.4	237.2	331.7
Net income attributable to noncontrolling interests	1.2	(2.8)	1.6	(4.6)
NET INCOME AVAILABLE TO IPG COMMON STOCKHOLDERS	$ 279.7	$ 165.6	$ 238.8	$ 327.1
Earnings per share, Basic	$ 0.72	$ 0.43	$ 0.61	$ 0.85
Earnings per share, Diluted	$ 0.71	$ 0.42	$ 0.61	$ 0.84
Weighted-average number of common shares outstanding, Basic	389.6	386.7	388.9	385.8
Weighted-average number of common shares outstanding, Diluted	393.9	391.8	392.6	390.3