VARIABLE INTEREST ENTITIES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Variable interest entities
Accounts receivable and accrued unbilled revenues	720.8us-gaap_ReceivablesNetCurrent	$ 699.8us-gaap_ReceivablesNetCurrent
Other current assets	43.0us-gaap_OtherAssetsCurrent	57.4us-gaap_OtherAssetsCurrent
Investment in AMP Trillium, LLC	556.0us-gaap_EquityMethodInvestments	550.6us-gaap_EquityMethodInvestments
Other long-term assets	262.2us-gaap_OtherAssetsNoncurrent	272.6us-gaap_OtherAssetsNoncurrent
Accounts payable	414.6us-gaap_AccountsPayableCurrent	490.7us-gaap_AccountsPayableCurrent
Other current liabilities	282.1us-gaap_OtherLiabilitiesCurrent	261.0us-gaap_OtherLiabilitiesCurrent
AMP Trillium, LLC
Variable interest entities
Accounts receivable and accrued unbilled revenues	12.1	9.5
Other current assets	2.0	2.0
Investment in AMP Trillium, LLC	5.4	5.5
Other long-term assets	11.3	11.8
Accounts payable	2.7	1.4
Other current liabilities	2.1	2.0
AMP Trillium, LLC \| Co-venturer
Variable interest entities
Variable interest entity, ownership interest (as a percent)	70.00%
AMP Trillium, LLC \| ITF
Variable interest entities
Variable interest entity, ownership interest (as a percent)	30.00%
EVO Trillium, LLC
Variable interest entities
Accounts receivable and accrued unbilled revenues	7.6	8.8
Other current assets	1.1	0.5
Other long-term assets	4.0	$ 1.7
EVO Trillium, LLC \| Co-venturer
Variable interest entities
Variable interest entity, ownership interest (as a percent)	85.00%
EVO Trillium, LLC \| ITF
Variable interest entities
Variable interest entity, ownership interest (as a percent)	15.00%

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer).

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Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Aggregate carrying amount of current liabilities (due within one year or within the normal operating cycle if longer) not separately disclosed in the balance sheet. Includes costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered and of liabilities not separately disclosed.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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