Insurance Operations - Statutory Capital and Surplus, and an Amount Representing Ten Percent of Total Liabilities for both UPCIC and APPCIC (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statutory Accounting Practices [Line Items]
Statutory capital and surplus	$ 12,900
UPCIC [Member]
Statutory Accounting Practices [Line Items]
Ten percent of total liabilities	72,633	$ 57,560
Statutory capital and surplus	307,686	313,753
APPCIC [Member]
Statutory Accounting Practices [Line Items]
Ten percent of total liabilities	572	464
Statutory capital and surplus	$ 16,633	$ 17,280

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://www.xbrl.org/2003/role/presentationRef
-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://www.xbrl.org/2003/role/presentationRef
-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