CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Consolidated revenue	$ 601.3	$ 585.7	$ 1,813.9	$ 1,700.9
Consolidated expenses:
Compensation and related expenses	253.6	238.7	761.3	722.9
Selling, general and administrative	102.8	91.9	314.4	269.7
Intangible amortization and impairments	30.1	21.2	76.5	65.1
Interest expense	19.6	22.1	62.6	67.6
Depreciation and other amortization	5.3	4.8	16.5	14.9
Other expenses (net)	10.2	10.9	33.4	35.9
Total consolidated expenses	421.6	389.6	1,264.7	1,176.1
Equity method income (net)	59.7	70.7	191.3	231.6
Investment and other income	11.0	16.1	36.7	46.7
Income before income taxes	250.4	282.9	777.2	803.1
Income tax expense	48.5	66.1	146.1	188.2
Net income	201.9	216.8	631.1	614.9
Net income (non-controlling interests)	(77.0)	(91.4)	(236.2)	(240.7)
Net income (controlling interest)	$ 124.9	$ 125.4	$ 394.9	$ 374.2
Average shares outstanding (basic) (in shares)	53.1	55.8	53.9	56.3
Average shares outstanding (diluted) (in shares)	55.4	58.3	56.3	58.8
Earnings per share (basic) (in dollars per share)	$ 2.35	$ 2.25	$ 7.32	$ 6.65
Earnings per share (diluted) (in dollars per share)	2.34	2.22	7.27	6.57
Dividends per share (in dollars per share)	$ 0.3	$ 0.2	$ 0.90	$ 0.6

The aggregate expense charged against earnings to allocate the cost of tangible assets to periods in which the assets are used and held and to allocate the cost of issuing debt to periods in which the debt is outstanding. As a noncash expense, this element is added back to net income when calculating cash provided by (used in) operations using the indirect method.

No definition available.