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Regulatory Matters - Additional Information (Detail) $ in Millions | 12 Months Ended
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Dec. 31, 2015 USD ($)
Regulated Operations [Abstract] |
Cash Dividend Declared and Paid | $ 13.5

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- Definition Amount of dividend income on nonoperating securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.7(a)) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
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- References No definition available. + Details
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