Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Other current assets:
Prepaid taxes	$ 74.1	$ 83.3
Prepaid expenses	69.2	66.9
Other	23.2	29.4
Total other current assets	166.5	179.6
Other assets
Investments in joint ventures	30.3	28.7
Deposits for real-estate leases	11.8	11.4
Indemnification assets related to acquisitions	20.7	19.2
Mutual funds and fixed deposits	55.1	55.0
Other	44.9	26.1
Total other assets	162.8	140.4
Accounts payable and accrued liabilities
Salaries and benefits	91.0	83.0
Incentive compensation	35.3	137.2
Customer credits, advanced payments and advanced billings	26.9	24.6
Self-insurance reserves	18.8	19.7
Dividends	6.8	78.2
Professional service fees	59.3	54.5
Interest accrued on debt	18.2	59.4
Accounts payable	14.4	22.2
Income taxes	41.5	11.5
Pension and other post retirement employee benefits	5.8	6.2
Other	73.5	70.1
Total accounts payable and accrued liabilities	391.5	566.6
Other liabilities
Pension and other post retirement employee benefits	270.0	261.7
Deferred rent-non-current portion	98.9	98.4
Interest accrued on UTPs	30.7	27.9
Other	19.8	27.5
Total other liabilities	$ 422.3	$ 417.2