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Per Share Data and Stockholders' Equity - Additional Information (Detail)
In Millions, unless otherwise specified |
9 Months Ended | ||||
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Sep. 30, 2013
Common Class A [Member]
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Sep. 30, 2012
Common Class A [Member]
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Sep. 30, 2013
5.0% Convertible Senior Notes [Member]
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Sep. 30, 2012
5.0% Convertible Senior Notes [Member]
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Aug. 31, 2012
5.0% Convertible Senior Notes [Member]
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| Capital Structure and Per Share Data [Line Items] | |||||
| Stated Interest rate on debt agreement | 5.00% | 5.00% | |||
| Convertible senior notes maturity year | 2029 | ||||
| Antidilutive stock options excluded in computation of diluted earnings per share | 0.9 | 1.3 | |||
| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Debt instrument maturity year. No definition available.
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| X | ||||||||||
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- Definition
Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Contractual interest rate for funds borrowed, under the debt agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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