Derivative Instruments Additional Information (Detail) € in Millions, MW in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) MW	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Mar. 31, 2017 EUR (€) MW
Derivative [Line Items]
Proceeds from Hedge, Investing Activities		$ 2,000,000
Derivative, Nonmonetary Notional Amount | MW	3.7			3.7
Payments for (Proceeds from) Hedge, Investing Activities	$ 0	0
Line of Credit Facility, Maximum Borrowing Capacity	1,200,000,000.0
Senior Loans [Member] | Term Loan [Member] | Dublin EfW Facility [Member]
Derivative [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | €				€ 250
Energy Hedges [Member]
Derivative [Line Items]
Proceeds from Hedge, Investing Activities	11,000,000	$ 14,000,000
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability	4,000,000
Derivative Liability, Noncurrent	$ 15,000,000		$ 18,000,000
Derivative Liability, Current			2,000,000
Sanfeng Environmental [Member]
Derivative [Line Items]
Derivative, Notional Amount			100,000,000
Proceeds from Sales of Assets, Investing Activities			105,000,000
Fiscal Year 2017 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MW	2.0			2.0
Fiscal Year 2018 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MW	1.7			1.7
Fair Value, Inputs, Level 2 [Member] | Energy Hedges [Member]
Derivative [Line Items]
Derivative Liability	$ 1,000,000		1,000,000
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability	19,000,000		$ 20,000,000
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Energy Hedges [Member]
Derivative [Line Items]
Derivative Liability	1,000,000
Derivative Asset, Current	$ 2,000,000