Insurance Operations - Statutory Capital and Surplus, and an Amount Representing Ten Percent of Total Liabilities for both UPCIC and APPCIC (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
UPCIC [Member]
Statutory Accounting Practices [Line Items]
Ten percent of total liabilities	$ 88,901	$ 72,633
Statutory capital and surplus	343,302	307,686
APPCIC [Member]
Statutory Accounting Practices [Line Items]
Ten percent of total liabilities	538	572
Statutory capital and surplus	$ 16,045	$ 16,633

The amount of statutory capital and surplus (stockholders' equity) as of the balance sheet date using prescribed or permitted statutory accounting practices (rather than GAAP, if different) of the state or country.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(c))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6486098&loc=d3e24708-158529

Name:	us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant