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Variable Interests and Variable Interest Entities (Narrative) (Details) - USD ($) $ in Millions | 9 Months Ended
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Sep. 30, 2016 | Sep. 30, 2015
Variable Interest Entities And Equity Investments [Abstract] |  |
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount | $ 0.0 |
Payments made to Pure Air | $ 16.0 | $ 16.5

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- References No definition available. + Details
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- Definition Variable Interest Entities and Equity Investments. + References No definition available. + Details
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- Definition The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=64801991&loc=d3e5728-111685 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=64801991&loc=d3e5747-111685 + Details
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