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v2.4.0.8

Senior Notes (Details) (USD $) | 12 Months Ended |  |  |
--- | --- | --- | --- | ---
Dec. 31, 2013 senior_note | Dec. 31, 2012 | Dec. 31, 2013 2022 Senior Notes [Member] | Dec. 31, 2013 2042 Senior Notes [Member] | Feb. 11, 2014 2024 Senior Notes [Member] Subsequent Event [Member]
Debt Disclosure [Abstract] |  |  |  |  |
Number of senior notes outstanding | 2 |  |  |  |
Deb Instrument [Line Items] |  |  |  |  |
Par value | $ 730,800,000 | $ 730,800,000 | $ 140,000,000 | $ 200,000,000 | $ 400,000,000.0
Interest rate |  |  | 5.25% | 6.375% | 4.25%

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- Definition Face (par) amount of debt instrument at time of issuance. + 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 + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 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 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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