GOODWILL AND OTHER INTANGIBLE ASSETS, Goodwill balance by reportable segment (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Goodwill [Line Items]
Goodwill	$ 186,847	$ 145,788
Service Centers [Member]
Goodwill [Line Items]
Goodwill	141,450	112,669
Innovative Pumping Solutions [Member]
Goodwill [Line Items]
Goodwill	28,258	15,980
Supply Chain Services [Member]
Goodwill [Line Items]
Goodwill	$ 17,139	$ 17,139

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details