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Net Income Per Common Share (Schedule of Average Shares Excluded From Diluted Net Income Per Common Share Computation) (Details) - $ / shares | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Average outstanding options | 438,000 | 1,498,000 | 543,000
Stock Options | Minimum |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Range of exercise prices | $ 79.01 | $ 49.20 | $ 67.53
Stock Options | Maximum |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Range of exercise prices | $ 95.25 | $ 95.25 | $ 95.25

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- Definition Stock options excluded because exercise prices were greater than average market price of shares + References No definition available. + Details
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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic net Income or Loss per outstanding limited partnership unit in the future and that were not included in the computation of diluted net income per limited partnership unit, because to do so would increase net income per unit amounts or decrease loss per unit amounts for the period presented. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257 + Details
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