Correction of Accounting Error (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013
Overstatement Of Goodwill [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error corrections	$ 9.2
Understatement Of Accounts Receivable [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error corrections	16.6
Understatement Of Accounts Payable [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error corrections	$ 7.4

Amount of each individual error being corrected in the correcting adjustment.

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 1

-Section N

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 250

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 1.N.Q3)

-URI http://asc.fasb.org/extlink&oid=6369664&loc=d3e30840-122693

Name:	us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration