Segment Reporting - Schedule of Operating Results by Segment (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues		$ 383,208	$ 437,485	$ 787,324	$ 834,640
Gross profit (loss)		26,052	81,884	106,208	165,281
R&D		3,070	3,962	5,912	8,480
Mark to market adjustment included in cost of operations		29,900	0	29,900	0
Losses (gains) on asset disposals and impairments, net		(6)	(9,009)	15	(9,027)
SG&A less pension MTM adjustment		(62,928)	(58,809)	(121,663)	(115,902)
Restructuring activities and spin-off transaction costs	$ (29,400)	(31,616)	(6,212)	(35,626)	(8,566)
Equity in income (loss) of investees		(616)	967	2,060	(1,104)
Mark to market adjustment included in selling, general and administrative expenses		(29,900)	0	(29,900)	0
Operating income (loss)		(72,585)	4,859	(55,319)	22,202
Operating Segments \| Global Power
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues		127,245	157,373	257,728	281,259
Gross profit (loss)		(9,068)	26,676	15,302	47,104
Operating Segments \| Global Services
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues		217,958	236,720	459,125	468,894
Gross profit (loss)		53,633	46,308	101,825	99,595
Operating Segments \| Industrial Environmental
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues		38,005	43,392	70,471	84,487
Gross profit (loss)		10,986	8,900	18,580	18,582
Cost of operations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Mark to market adjustment included in cost of operations		29,499	0	29,499	0
Mark to market adjustment included in selling, general and administrative expenses		(29,499)	0	(29,499)	0
Selling, General and Administrative Expenses
Segment Reporting, Other Significant Reconciling Item [Line Items]
Mark to market adjustment included in cost of operations		401	0	401	0
Mark to market adjustment included in selling, general and administrative expenses		$ (401)	$ 0	$ (401)	$ 0

Defined Benefit Plan, Actuarial Gain (Loss), Mark to Market Adjustment

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R&D

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SG&A less pension MTM adjustment

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- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

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-Topic 360
-SubTopic 10
-Section 45
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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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-Name Regulation S-X (SX)
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The net result for the period of deducting operating expenses from operating revenues.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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