Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Other current assets:
Prepaid taxes	$ 46.1	$ 83.3
Prepaid expenses	57.0	66.9
Other	24.5	29.4
Total other current assets	127.6	179.6
Other assets
Investments in joint ventures	18.6	28.7
Deposits for real-estate leases	11.4	11.4
Indemnification assets related to acquisitions	20.7	19.2
Mutual funds and fixed deposits	61.0	55.0
Other	42.9	26.1
Total other assets	154.6	140.4
Accounts payable and accrued liabilities
Salaries and benefits	71.4	83.0
Incentive compensation	101.4	137.2
Customer credits, advanced payments and advanced billings	27.2	24.6
Self-insurance reserves	21.7	19.7
Dividends	7.1	78.2
Professional service fees	51.2	54.5
Interest accrued on debt	23.1	59.4
Accounts payable	28.0	22.2
Income taxes	7.9	11.5
Restructuring	9.6
Pension and other post retirement employee benefits	6.4	6.2
Other	95.3	70.1
Total accounts payable and accrued liabilities	450.3	566.6
Other liabilities
Pension and other post retirement employee benefits	256.1	261.7
Deferred rent-non-current portion	98.9	98.4
Interest accrued on UTPs	33.5	27.9
Legacy and other tax matters	1.2	1.7
Other	23.2	27.5
Total other liabilities	$ 412.9	$ 417.2