Goodwill and intangible assets.

No definition available.

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- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

+ Details

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- Definition

Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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- Definition

Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

+ References

No definition available.

+ Details

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- Definition

Amount of fair value of reporting unit in excess of carrying amount.

+ References

No definition available.

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Goodwill and Intangible Assets - Additional Information (Detail)		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 01, 2018 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) ReportingUnit	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) ReportingUnit
Goodwill And Intangible Assets [Line Items]
Number of reporting units with carrying amount of zero or less than zero \| ReportingUnit				0		0
Carrying amount of reporting unit		$ 0		$ 0		$ 0
Amortization of intangible assets		128,000	$ 113,000	373,000	$ 308,000
HSB Insurance, Inc. [Member] \| Customer list intangible [Member]
Goodwill And Intangible Assets [Line Items]
Intangible gross carrying amount	$ 325,000
Maximum [Member]
Goodwill And Intangible Assets [Line Items]
Carrying amount of reporting unit		$ 0		$ 0		$ 0