Supplementary Data (Tables)
 3 Months Ended
Mar. 31, 2017
Supplementary Data [Abstract]  
Accrued Liabilities
The following table presents the components of accrued liabilities.
 
March 31,
2017
 
December 31,
2016
Salaries, benefits and related expenses
$
301.7

 
$
499.0

Acquisition obligations
91.1

 
77.5

Office and related expenses
46.7

 
46.7

Interest
17.2

 
17.3

Other
115.3

 
153.5

Total accrued liabilities
$
572.0

 
$
794.0
Other Income (Expense), Net
Results of operations for the three months ended March 31, 2017 and 2016 include certain items that are not directly associated with our revenue-producing operations.
 
Three months ended
March 31,
 
2017
 
2016
Gains (losses) on sales of businesses and investments
$
1.0

 
$
(16.3
)
Other expense, net
(0.2
)
 
(2.9
)
Total other income (expense), net
$
0.8

 
$
(19.2
)
Share Repurchase Program
The following table presents our share repurchase activity under our share repurchase programs for the three months ended March 31, 2017 and 2016.
 
Three months ended
March 31,
 
2017
 
2016
Number of shares repurchased
2.3

 
2.5

Aggregate cost, including fees
$
55.0

 
$
53.7

Average price per share, including fees
$
23.85

 
$
21.67
Redeemable Noncontrolling Interest
The following table presents changes in our redeemable noncontrolling interests.
 
Three months ended
March 31,
 
2017
 
2016
Balance at beginning of period
$
252.8

 
$
251.9

Change in related noncontrolling interests balance
(4.5
)
 
(2.9
)
Changes in redemption value of redeemable noncontrolling interests:
 
 
 
Redemptions and other
(12.7
)
 
(9.0
)
Redemption value adjustments
5.6

 
6.3

Balance at end of period
$
241.2

 
$
246.3