Variable Interest Entity - Additional Information (Detail) - PHI Century Limited [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investment in the common stock	49.00%
PHIC's date of incorporation	May 26, 2011
Earnings (loss) in equity of unconsolidated affiliate	$ 0.2	$ (1.0)
Trade receivables	4.8	4.0
Other assets	0.5	$ 0.5
Accounts Receivable - Other [Member]
Variable Interest Entity [Line Items]
Loan to affiliate	$ 0.4

Equity In Earnings (Loss) Of Unconsolidated Affiliates

No definition available.

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- Definition

Investment in variable interest entity.

+ References

No definition available.

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- Definition

Trade receivables.

+ References

No definition available.

+ Details

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- Definition

Amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership, due within 1 year (or 1 business cycle).

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

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- Definition

Date the relationship between reporting entity and the Variable Interest Entity (VIE) began, in CCYY-MM-DD format.

+ References

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