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Computation of Earnings Per Common Share - Narratives (Details) - $ / shares | Jul. 29, 2017 | Sep. 15, 2015
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Convertible Note Hedge |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |
Debt instrument, convertible, conversion price (per share) | $ 96.89 | $ 96.89
0.75% Convertible Senior Notes Due 2021 |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |
Debt, interest rate (in percent) | 0.75% |
Debt instrument, convertible, conversion price (per share) |  | 96.89
Class of earrant or right, exercise price of warrants or rights (per warrant) | $ 130.43 | $ 130.43

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- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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