Business Disposition - Schedule of Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Current assets	$ 921.0	$ 837.4
Restricted cash	35.2	24.2
Property and equipment, net	656.9	654.5
LIABILITIES
Current maturities of long-term debt	7.6	7.8
Long-term debt	993.2	957.2
Contran | Trade Accounts Payables
LIABILITIES
Payable to Contran	32.5	31.4
Waste Management
ASSETS
Current assets	14.4	17.2
Restricted cash	23.0	21.6
Property and equipment, net	135.9	138.5
LIABILITIES
Current maturities of long-term debt	3.2	3.3
Long-term debt	67.2	68.0
Accrued noncurrent closure and post closure costs	30.0	29.4
Waste Management | Capitalized Operating Permits
ASSETS
Operating permits	42.4	42.9
Waste Management | Contran | Trade Accounts Payables
LIABILITIES
Payable to Contran	$ 32.5	$ 31.4