Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Other current assets:
Prepaid taxes	$ 74.9	$ 47.0
Prepaid expenses	89.9	65.7
Other	35.7	28.1
Total other current assets	200.5	140.8
Other assets
Investments in joint ventures	83.4	26.3
Deposits for real-estate leases	12.3	10.8
Indemnification assets related to acquisitions	16.8	16.5
Mutual funds and fixed deposits	27.0	32.7
Other	29.0	25.9
Total other assets	168.5	112.2
Accounts payable and accrued liabilities
Salaries and benefits	93.2	89.3
Incentive compensation	180.0	151.1
Accrued settlement charge		863.8
Customer credits, advanced payments and advanced billings	23.6	28.4
Self-insurance reserves	9.8	11.1
Dividends	5.3	78.5
Professional service fees	45.6	40.4
Interest accrued on debt	37.5	59.2
Accounts payable	29.2	28.4
Income taxes	49.8	16.8
Restructuring Reserve Current	0.6	6.3
Pension and other post retirement employee benefits	7.7	6.1
Accrued Royalties, Current	17.3	1.8
Other	77.9	63.1
Total accounts payable and accrued liabilities	577.5	1,444.3
Other liabilities
Pension and other post retirement employee benefits	268.3	264.1
Deferred rent-non-current portion	104.6	98.3
Interest accrued on UTPs	48.9	34.1
Legacy and other tax matters	1.2	1.2
Other	24.3	27.5
Total other liabilities	$ 447.3	$ 425.2