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Subsidiary Dividend Restrictions - Additional Information (Detail) - Wright Flood $ in Millions | 9 Months Ended
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Sep. 30, 2018 USD ($)
Dividend Restrictions [Line Items] |
Dividend rate as a percentage of net income | 100.00%
Maximum dividend payout that may be made without prior approval | $ 4.8
Maximum |
Dividend Restrictions [Line Items] |
Dividend rate as a percentage of net income | 10.00%

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- Definition Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition Amount of dividends that can be declared or paid without approval of regulatory agency. + 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.(e)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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