Financial Instruments - Additional Information (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2012
Derivative [Line Items]
Fair value of interest rate swaps liability	$ 3.3
Maximum
Derivative [Line Items]
Loss in fair value of interest rate swaps	0.1
Foreign Exchange Forward
Derivative [Line Items]
Fair value of the forward contracts liability	$ (0.4)

Fair value as of the balance sheet date of foreign currency derivative assets, net of foreign currency derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Name:	us-gaap_ForeignCurrencyDerivativesAtFairValueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant