v2.4.0.6

Debt Credit Facility Additional Information (Details) (USD $) |  |  | 3 Months Ended |  |
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Mar. 31, 2013 | Aug. 05, 2011 | Mar. 31, 2013 U.S. Domestic Subsidiaries [Member] | Mar. 31, 2013 First-Tier Foreign Subsidiaries [Member] Non-voting Stock [Member] | Mar. 31, 2013 Scheduled Quarterly Repayments through June 2013 [Domain] | Mar. 31, 2013 Scheduled Quarterly Repayments September 2013 through June 2014 [Domain] | Mar. 31, 2013 Scheduled Quarterly Repayments September 2014 through June 2016 [Domain] | Mar. 31, 2013 Minimum [Member] | Mar. 31, 2013 Maximum [Member] | Mar. 31, 2013 Maximum [Member] First-Tier Foreign Subsidiaries [Member] Voting Stock [Member] | Mar. 31, 2013 Alternate base rate (1) [Member] | Mar. 31, 2013 Alternate base rate (2) [Member] | Mar. 31, 2013 Alternate base rate (3) [Member] | Mar. 31, 2013 LIBOR interest rate [Member] | Apr. 02, 2012 Increased Line of Credit Borrowing Capacity [Member] | Aug. 05, 2011 Line of Credit Borrowing Capacity at Inception [Member]
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  | $ 300,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 660,000,000 | 500,000,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage |  |  |  |  |  |  |  | 0.20% | 0.40% |  |  |  |  |  |  |
Pledge of Capital Stock |  |  | 100.00% | 100.00% |  |  |  |  |  | 66.00% |  |  |  |  |  |
Repayments of Secured Debt |  |  |  |  | 3,800,000 | 5,600,000 | 7,500,000 |  |  |  |  |  |  |  |  |
Debt Instrument, Description of Variable Rate Basis |  |  |  |  |  |  |  |  |  |  | the prime rate | the Federal Reserve effective rate | one month LIBOR | the LIBOR rate |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  |  |  | 0.50% | 1.00% | 1.25% |  |
Applicable Interest Rate |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.46% |  |
Line of credit facility, amount outstanding | 125,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Letters of Credit Outstanding, Amount | 47,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, remaining borrowing capacity | $ 487,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition 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. + References No definition available. + Details
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Balance Type: | na
Period Type: | duration

X
- Definition The percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
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Period Type: | instant

X
- Definition The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
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X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 21 -Paragraph 16, 20 -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. + Details
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Balance Type: | credit
Period Type: | instant

X
- Definition The effective interest rate at the end of the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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X
- Details
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X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount borrowed under the credit facility as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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Balance Type: | credit
Period Type: | instant

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 4 -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 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility. + References No definition available. + Details
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X
- Definition The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 -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 -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3291-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b -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. + Details
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