The percentage of the pledged capital stock as security for the payment and performance in full of all obligations to a creditor. The pledge effectively gives the creditor a lien on the security interest of the pledged capital stock.

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Prepaid debt fees represent the capitalized direct costs incurred related to the issuance of debt. These costs are amortized to interest expense over the lives of the respective borrowings using the effective interest method. When debt is repaid early, or first becomes convertible the related portion of unamortized prepaid debt fees is written-off and included in interest expense.

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The percentage points added to the reference rate to compute the variable rate on the debt instrument.

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The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

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The effective interest rate at the end of the reporting period.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Amount borrowed under the credit facility as of the balance sheet date.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

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The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Debt Credit Facility Additional Information (Details)							3 Months Ended																		3 Months Ended		9 Months Ended
Debt Credit Facility Additional Information (Details)	Sep. 30, 2011 USD ($)	Dec. 31, 2010 USD ($)	Sep. 30, 2011 LIBOR interest rate [Member] 2011 Senior Secured Credit Facility [Member]	Sep. 30, 2011 LIBOR interest rate [Member] 2011 Senior Secured Credit Facility [Member] USD Denominated Term Loan [Member] USD ($)	Sep. 30, 2011 U.S. Prime rate [Member] 2011 Senior Secured Credit Facility [Member]	Sep. 30, 2011 U.S. Prime rate [Member] 2011 Senior Secured Credit Facility [Member] Line of Credit [Member] USD ($)	Sep. 30, 2011 Maximum [Member] First-Tier Foreign Subsidiaries [Member] Voting Stock [Member]	Sep. 30, 2011 2007 Senior Secured Credit Facility [Member] USD ($)	Dec. 31, 2010 2007 Senior Secured Credit Facility [Member] Credit Facilities [Member] USD ($)	Sep. 30, 2011 2007 Senior Secured Credit Facility [Member] USD Denominated Term Loan [Member] USD ($)	Dec. 31, 2010 2007 Senior Secured Credit Facility [Member] USD Denominated Term Loan [Member] USD ($)	Sep. 30, 2011 2007 Senior Secured Credit Facility [Member] EUR Denominated Term Loan [Member] USD ($)	Dec. 31, 2010 2007 Senior Secured Credit Facility [Member] EUR Denominated Term Loan [Member] USD ($)	Sep. 30, 2011 2011 Senior Secured Credit Facility [Member] USD ($)	Aug. 05, 2011 2011 Senior Secured Credit Facility [Member] USD ($)	Dec. 31, 2010 2011 Senior Secured Credit Facility [Member] USD ($)	Sep. 30, 2011 2011 Senior Secured Credit Facility [Member] Credit Facilities [Member] USD ($)	Aug. 05, 2011 2011 Senior Secured Credit Facility [Member] Credit Facilities [Member] EUR (€)	Sep. 30, 2011 2011 Senior Secured Credit Facility [Member] USD Denominated Term Loan [Member] USD ($)	Aug. 05, 2011 2011 Senior Secured Credit Facility [Member] USD Denominated Term Loan [Member] USD ($)	Dec. 31, 2010 2011 Senior Secured Credit Facility [Member] USD Denominated Term Loan [Member] USD ($)	Sep. 30, 2011 2011 Senior Secured Credit Facility [Member] Line of Credit [Member] USD ($)	Aug. 05, 2011 2011 Senior Secured Credit Facility [Member] Line of Credit [Member] USD ($)	Dec. 31, 2010 2011 Senior Secured Credit Facility [Member] Line of Credit [Member] USD ($)	Sep. 30, 2011 U.S. Domestic Subsidiaries [Member]	Sep. 30, 2011 First-Tier Foreign Subsidiaries [Member] Non-voting Stock [Member]	Sep. 30, 2011 Scheduled Quarterly Repayments September 2011 through June 2013 [Domain] USD ($)	Sep. 30, 2011 Scheduled Quarterly Repayments September 2013 through June 2014 [Domain] USD ($)	Sep. 30, 2011 Scheduled Quarterly Repayments September 2014 through June 2016 [Domain] USD ($)
Debt Instrument [Line Items]
Long-term Debt	$ 496,252,000	$ 610,941,000								$ 0	$ 218,642,000	$ 0	$ 174,031,000						$ 296,252,000		$ 0	$ 200,000,000		$ 0
Debt Instrument, Face Amount																		800,000,000		300,000,000
Line of credit facility, maximum borrowing capacity																							500,000,000
Pledge of Capital Stock							66.00%																		100.00%	100.00%
Repayments of Secured Debt																											3,800,000	5,600,000	7,500,000
Line of credit facility, amount outstanding				190,000,000		10,000,000								200,000,000		0
Letters of Credit Outstanding, Amount																						35,900,000
Debt Instrument, Interest Rate at Period End			1.73%		3.75%
Debt Instrument, Basis Spread on Variable Rate			1.50%		0.50%
Line of credit facility, remaining borrowing capacity																						264,100,000
Write off of Deferred Debt Issuance Cost								2,400,000
Prepaid Debt Fees Noncurrent									$ 4,483,000						$ 6,200,000		$ 5,963,000