Reclassifications out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI, net of tax	$ (581)	$ (686)	$ 1,295	$ (1,048)
Net investment income	27,614	28,416	54,066	57,943
Net realized investment gains (losses)	57	(1,146)	(77)	(1,003)
Portion of OTTI previously recognized in OCI		102	121	102
Income (Loss) Before Taxes	5,701	(4,955)	(903)	5,698
Income Tax Expense (Benefit)	0	0	0	0
Net Income (Loss)	5,701	(4,955)	(903)	5,698
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Holding Gains (Losses) on AFS Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized investment gains (losses)	(68)	42	1,732	(1,120)
Portion of OTTI previously recognized in OCI		(102)	(121)	(102)
Income (Loss) Before Taxes	(68)	(60)	1,611	(1,222)
Income Tax Expense (Benefit)	0	0	0	0
Net Income (Loss)	(68)	(60)	1,611	(1,222)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Holding Gains (Losses) on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income	(513)	(626)	(316)	174
Income (Loss) Before Taxes	(513)	(626)	(316)	174
Income Tax Expense (Benefit)	0	0	0	0
Net Income (Loss)	$ (513)	$ (626)	$ (316)	$ 174