Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized investment (gains) losses	$ 6,443	$ 2,629
Other than temporary impairment losses on investments	1,050	341
Total before tax	(1,953)	(3,238)
Income tax expense (benefit)	(5,172)	(3,556)
Net income (loss)	(7,125)	(6,794)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(970)	(1,799)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains and Losses on Available for Sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized investment (gains) losses	(2,535)	(3,381)
Other than temporary impairment losses on investments	1,050	341
Total before tax	(1,485)	(3,040)
Income tax expense (benefit)	515	1,158
Net income (loss)	$ (970)	(1,882)
Reclassification out of Accumulated Other Comprehensive Income | Foreign Currency Items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized investment (gains) losses		128
Income tax expense (benefit)		(45)
Net income (loss)		$ 83