Segment Information - Summary of Segment Assets Reconciled to Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total assets	$ 670,064	$ 636,986
Consolidation, Eliminations [Member]
Segment Reporting Information [Line Items]
Total assets	(98,712)	(42,527)
Insurance Operations [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	651,927	591,101
Corporate and Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	$ 116,849	$ 88,412