Represents the amount of debt acquired in a business combination that was not refinanced through proceeds from debt.

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Represents the number of locations where the acquiree company has the business.

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Represents the number of real estate properties of the acquired entity, which were leased by subsidiaries of the reporting entity.

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Represents the number of service centers acquired by the entity in a business acquisition.

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The pro forma acquisition and related costs for the period, as if the business combination or combinations had been completed at the beginning of a period.

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Amount of current and long-term debt assumed at the acquisition date.

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Amount of other current and noncurrent liabilities assumed at the acquisition date.

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The amount of other current and noncurrent assets recognized as of the acquisition date.

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The number of countries in which the entity's customers operate as of balance sheet date.

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

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Amount of assets acquired at the acquisition date.

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of deferred tax asset attributable to deductible temporary differences and carryforwards that are expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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The amount of inventory recognized as of the acquisition date.

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Amount of liabilities assumed at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

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Face (par) amount of debt instrument at time of issuance.

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Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The number of countries in which the entity operates as of balance sheet date.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Acquisitions (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended					2 Months Ended				0 Months Ended		6 Months Ended	9 Months Ended		0 Months Ended	6 Months Ended	9 Months Ended		0 Months Ended	3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Apr. 12, 2013 Term loan expiring April 4, 2018	Apr. 12, 2013 Senior unsecured notes due 2023	Sep. 30, 2014 NIS	Sep. 30, 2014 AMS	Aug. 01, 2014 AMS item	Aug. 01, 2014 AMS Minimum item	Apr. 30, 2013 Travel Main item	Apr. 12, 2013 Metals USA item	Sep. 30, 2013 Metals USA	Sep. 30, 2014 Metals USA	Sep. 30, 2013 Metals USA	May 16, 2014 Metals USA Non-core roofing business	Sep. 30, 2013 Metals USA Non-core roofing business	Sep. 30, 2014 Metals USA Non-core roofing business	Sep. 30, 2014 Haskins Steel Co., Inc. (Haskins Steel)	Aug. 01, 2014 2014 acquisitions	Sep. 30, 2014 2014 acquisitions
Acquisitions
Net sales	$ 2,705.1	$ 2,443.5	$ 7,874.9	$ 6,917.1				$ 3.5	$ 45.1					$ 828.8	$ 1,360.0			$ 17.1	$ 9.6	$ 23.0
Number of countries of the acquiree entity										4
Number of countries in which entity's customers operate											40
Number of locations of the acquiree entity										8
Number of real estate properties of acquired entity which were leased by subsidiaries of reporting entity												18
Total transaction value												78.9	1,250.0								145.7
Value of debt assumed												43.8	486.1								41.7
Number of service centers acquired													44
Proceeds from sale of business			26.2	7.0													26.2
Pre-tax loss on sale of business																	1.1
Purchase price													766.8
Acquired debt not refinanced through proceeds from debt													12.3
Face amount of debt, proceeds from which is used to fund transaction						500.0	500.0
Transaction related costs				11.4																		0.8
Allocation of the total purchase price of acquisitions to the fair value of the assets acquired and liabilities assumed
Cash															3.2
Accounts receivable															206.0
Inventories															379.5
Property, plant and equipment															242.6
Goodwill	1,707.5		1,707.5		1,691.6										382.7
Intangible assets subject to amortization															137.6
Intangible assets not subject to amortization															203.0
Other current and long-term assets															9.1
Total assets acquired															1,563.7
Current and long-term debt															486.1
Deferred taxes															184.4
Other current and long-term liabilities															126.4
Total liabilities assumed															796.9
Net assets acquired															766.8
Pro forma financial information
Acquisition and related costs																48.7
Pro forma:
Net sales																7,447.1
Net income attributable to Reliance																$ 267.1
Diluted earnings per common share attributable to Reliance shareholders (in dollars per share)																$ 3.45
Basic earnings per common share attributable to Reliance shareholders (in dollars per share)																$ 3.48