The maximum period over which the fair value of restricted stock and restricted stock units are amortized.

No definition available.

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The historical period upon which annual expected stock price volatility is based.

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No definition available.

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Represents the daily treasury yield curve period, in years, upon which the average risk-free interest rate is based.

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Represents the assumed correlation between the total shareholder return for the entities stock and the S&P 500 Composite Index and the S&P Composite 1500 Industrials Index.

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Represents the amount by which common stock available is reduced for each share granted.

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Represents the percentage of the target award, which each participant can earn under the plan.

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No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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-Publisher FASB
-Name Accounting Standards Codification
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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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-Publisher FASB
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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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-Publisher FASB
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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

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Percentage of vesting of share-based compensation awards.

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Shareholders' Equity and Long-Term Incentive Compensation - Long-Term Incentive Compensation (Details) $ in Millions			12 Months Ended
	Mar. 01, 2017	Mar. 02, 2016	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014	Dec. 31, 2013
Assumptions in determining the fair value of awards granted
Historical period upon which annual expected stock price volatility is based			3 years
Maximum
Stock-based Compensation
Maximum period over which the fair value of restricted stock shares and restricted stock units are amortized			3 years
Assumptions in determining the fair value of awards granted
Daily treasury yield curve period upon which average risk-free interest rate is based			3 years
Maximum \| 2002 Stock Compensation Plan
Stock-based Compensation
Shares available for grant (in shares) \| shares			1,682,000
Maximum \| Directors' Plan
Stock-based Compensation
Shares available for grant (in shares) \| shares			27,000.000
Minimum
Assumptions in determining the fair value of awards granted
Daily treasury yield curve period upon which average risk-free interest rate is based			1 year
PSU's, RSU's, RS's, and Stock Options
Stock-based Compensation
Compensation expense \| $			$ 12.0	$ 12.7	$ 33.9
PSU's, RSU's, and RS's \| Maximum
Stock-based Compensation
Vesting period			3 years
PSU's, RSU's, and RS's \| Minimum
Stock-based Compensation
Vesting period			1 year
Restricted stock shares and restricted stock units
Stock-based Compensation
Related tax benefit \| $			$ 4.6	$ 4.8	$ 12.9
Restricted stock shares and restricted stock units \| 2002 Stock Compensation Plan
Stock-based Compensation
Reduction of shares available for grant (in shares) \| shares			2
Restricted stock shares and restricted stock units \| Directors' Plan
Stock-based Compensation
Vesting period			1 year	1 year	1 year
PSU's
Stock-based Compensation
Vesting period			3 years	3 years	3 years
Assumptions in determining the fair value of awards granted
Annual expected stock price volatility	41.03%	36.91%
Annual expected dividend yield	0.00%	0.00%
Risk-free interest rate	1.52%	0.97%
Correlation between total shareholder return for SPX and the applicable S&P index	0.3685	0.3354
PSU's \| 2002 Stock Compensation Plan
Stock-based Compensation
Reduction of shares available for grant (in shares) \| shares			3.0
PSU's \| S&P Composite 1500 Industrials Index
Assumptions in determining the fair value of awards granted
Annual expected stock price volatility	34.49%	32.94%
Risk-free interest rate	1.52%	0.97%
PSU's \| Maximum
Stock-based Compensation
Maximum vesting attainment (percentage)			150.00%
Percentage of target award, which can be earned by each eligible employee						125.00%	125.00%
PSU's \| Minimum
Stock-based Compensation
Percentage of target award, which can be earned by each eligible employee						25.00%	25.00%
PSU's \| Discontinued Operations, Disposed of by Means Other than Sale, Spinoff \| SPX Flow, Inc
Stock-based Compensation
Percentage of target award, which can be earned by each eligible employee			50.00%	50.00%
Additional stock compensation expense \| $					$ 2.1
Long Term Cash Awards
Stock-based Compensation
Vesting period			3 years
Compensation expense \| $			$ 3.8	$ 1.0