CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Consolidated revenue	$ 600.1	$ 570.9	$ 1,212.6	$ 1,115.2
Consolidated expenses:
Compensation and related expenses	241.0	242.2	507.7	484.2
Selling, general and administrative	105.2	89.1	211.6	177.8
Intangible amortization and impairments	23.2	22.0	46.4	43.9
Interest expense	21.4	23.1	43.0	45.6
Depreciation and other amortization	5.7	4.9	11.2	10.1
Other expenses (net)	11.1	13.6	23.2	25.0
Total consolidated expenses	407.6	394.9	843.1	786.6
Equity method income (net)	35.3	75.0	131.6	160.9
Investment and other income	11.5	15.9	25.7	30.7
Income before income taxes	239.3	266.9	526.8	520.2
Income tax expense	34.1	62.5	97.5	122.2
Net income	205.2	204.4	429.3	398.0
Net income (non-controlling interests)	(88.2)	(78.1)	(159.3)	(149.2)
Net income (controlling interest)	$ 117.0	$ 126.3	$ 270.0	$ 248.8
Average shares outstanding (basic) (in shares)	54.0	56.3	54.3	56.5
Average shares outstanding (diluted) (in shares)	54.2	58.7	56.8	59.0
Earnings per share (basic) (in dollars per share)	$ 2.17	$ 2.24	$ 4.97	$ 4.40
Earnings per share (diluted) (in dollars per share)	2.16	2.22	4.92	4.35
Dividends per share (in dollars per share)	$ 0.30	$ 0.20	$ 0.60	$ 0.40

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.