Additional Details Related to Certain Balance Sheet Captions (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Other current assets
Prepaid taxes	$ 94.0	$ 31.8
Prepaid expenses	42.8	47.3
Other	10.8	12.8
Total other current assets	147.6	91.9
Other assets
Investments in joint ventures	35.1	38.3
Deposits for real-estate leases	9.0	10.0
Other	45.8	47.7
Total other assets	89.9	96.0
Accounts payable and accrued liabilities
Salaries and benefits	63.2	79.2
Incentive compensation	62.0	162.6
Profit sharing contribution	0	12.6
Customer credits, advanced payments and advanced billings	23.0	21.5
Dividends	3.4	47.7
Professional service fees	35.5	30.2
Interest accrued on debt	23.1	23.4
Accounts payable	14.9	14.3
Income taxes	2.4	56.1
Restructuring	0	0
Deferred rent-current portion	1.0	1.1
Pension and other post retirement employee benefits	4.4	4.4
Interest accrued on UTPs	0	0
Other	43.8	46.4
Total accounts payable and accrued liabilities	312.8	555.3
Self-insurance reserves	36.1	55.8
Other liabilities
Pension and other post retirement employee benefits	206.8	213.3
Deferred rent-non-current portion	105.7	110.2
Interest accrued on UTPs	14.4	10.6
Legacy and other tax matters	38.1	37.1
Other	47.9	38.9
Total other liabilities	$ 412.9	$ 410.1