SEGMENT INFORMATION - Summarized financial information by segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	$ 144,487	$ 142,737
SAP underwriting profit (loss)	653	12,528
GAAP adjustments	(1,338)	(2,052)
GAAP underwriting profit (loss)	(685)	10,476
Net investment income	11,007	12,230
Net realized investment losses	(627)	(1,085)
Other income (loss)	(410)	(11)
Interest expense	84	84
Other expenses	761	649
Income before income tax expense	8,440	20,877
Reconciliation of assets from segment to consolidated
Assets	2,149,127		$ 2,131,694
Eliminations	(554,504)		(540,249)
Reclassifications	(3,013)		(2,632)
Total assets	1,591,610		1,588,813
Property and casualty insurance [Member]
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	113,648	110,446
SAP underwriting profit (loss)	(2,594)	10,466
GAAP adjustments	(1,007)	(1,861)
GAAP underwriting profit (loss)	(3,601)	8,605
Net investment income	8,015	8,771
Net realized investment losses	(597)	(846)
Other income (loss)	161	132
Interest expense	84	84
Other expenses	179	157
Income before income tax expense	3,715	16,421
Reconciliation of assets from segment to consolidated
Assets	1,119,323		1,122,037
Eliminations	0		0
Reclassifications	(1,716)		0
Total assets	1,117,607		1,122,037
Reinsurance [Member]
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	30,839	32,291
SAP underwriting profit (loss)	3,247	2,062
GAAP adjustments	(331)	(191)
GAAP underwriting profit (loss)	2,916	1,871
Net investment income	2,983	3,457
Net realized investment losses	(30)	(239)
Other income (loss)	(571)	(143)
Interest expense	0	0
Other expenses	0	0
Income before income tax expense	5,298	4,946
Reconciliation of assets from segment to consolidated
Assets	465,017		455,493
Eliminations	0		0
Reclassifications	0		(1,932)
Total assets	465,017		453,561
Parent company [Member]
Reconciliation of operating profit loss from segment to consolidated
Premiums earned	0	0
SAP underwriting profit (loss)	0	0
GAAP adjustments	0	0
GAAP underwriting profit (loss)	0	0
Net investment income	9	2
Net realized investment losses	0	0
Other income (loss)	0	0
Interest expense	0	0
Other expenses	582	492
Income before income tax expense	(573)	$ (490)
Reconciliation of assets from segment to consolidated
Assets	564,787		554,164
Eliminations	(554,504)		(540,249)
Reclassifications	(1,297)		(700)
Total assets	$ 8,986		$ 13,215