INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Reconciliation of available-for-sale securities from cost basis to fair value

The amortized cost and estimated fair value of securities available-for-sale as of December 31, 2016 and 2015 are as follows.  All securities are classified as available-for-sale and are carried at fair value.

December 31, 2016	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair values
($ in thousands)
Securities available-for-sale:
Fixed maturity securities:
U.S. treasury	$	7,841	$	—	$	11	$	7,830
U.S. government-sponsored agencies	249,495		311		10,609		239,197
Obligations of states and political subdivisions	319,663		17,034		940		335,757
Commercial mortgage-backed	37,964		741		1,133		37,572
Residential mortgage-backed	102,307		1,435		7,308		96,434
Other asset-backed	26,592		732		931		26,393
Corporate	445,663		12,232		1,379		456,516
Total fixed maturity securities	1,189,525		32,485		22,311		1,199,699
Equity securities:
Common stocks:
Financial services	22,922		12,410		210		35,122
Information technology	19,832		10,739		29		30,542
Healthcare	16,092		8,700		85		24,707
Consumer staples	13,438		5,787		125		19,100
Consumer discretionary	14,812		7,672		163		22,321
Energy	14,276		4,873		78		19,071
Industrials	13,005		11,258		18		24,245
Other	13,071		5,345		32		18,384
Non-redeemable preferred stocks	20,031		483		167		20,347
Total equity securities	147,479		67,267		907		213,839
Total securities available-for-sale	$	1,337,004	$	99,752	$	23,218	$	1,413,538

December 31, 2015	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair values
($ in thousands)
Securities available-for-sale:
Fixed maturity securities:
U.S. treasury	$	12,566	$	23	$	—	$	12,589
U.S. government-sponsored agencies	202,486		1,817		1,637		202,666
Obligations of states and political subdivisions	319,940		24,419		—		344,359
Commercial mortgage-backed	44,433		1,692		17		46,108
Residential mortgage-backed	94,279		1,059		6,795		88,543
Other asset-backed	17,000		883		39		17,844
Corporate	439,513		12,992		3,589		448,916
Total fixed maturity securities	1,130,217		42,885		12,077		1,161,025
Equity securities:
Common stocks:
Financial services	24,557		9,731		333		33,955
Information technology	19,427		8,807		132		28,102
Healthcare	15,599		10,359		64		25,894
Consumer staples	11,136		7,090		26		18,200
Consumer discretionary	10,270		8,658		5		18,923
Energy	16,384		5,972		1,288		21,068
Industrials	11,525		8,902		11		20,416
Other	17,246		3,672		235		20,683
Non-redeemable preferred stocks	18,032		1,168		198		19,002
Total equity securities	144,176		64,359		2,292		206,243
Total securities available-for-sale	$	1,274,393	$	107,244	$	14,369	$	1,367,268

Estimated fair value and gross unrealized losses associated with investment securities

The following tables set forth the estimated fair values and gross unrealized losses associated with investment securities that were in an unrealized loss position as of December 31, 2016 and 2015, listed by length of time the securities were in an unrealized loss position.

December 31, 2016	Less than twelve months				Twelve months or longer				Total
($ in thousands)	Fair values		Unrealized losses		Fair values		Unrealized losses		Fair values		Unrealized losses
Fixed maturity securities:
U.S. treasury	$	7,830	$	11	$	—	$	—	$	7,830	$	11
U.S. government-sponsored agencies	202,900		10,609		—		—		202,900		10,609
Obligations of states and political subdivisions	43,777		940		—		—		43,777		940
Commercial mortgage-backed	21,695		1,133		—		—		21,695		1,133
Residential mortgage-backed	26,217		1,232		23,625		6,076		49,842		7,308
Other asset-backed	19,091		931		—		—		19,091		931
Corporate	82,657		1,273		8,625		106		91,282		1,379
Total fixed maturity securities	404,167		16,129		32,250		6,182		436,417		22,311
Equity securities:
Common stocks:
Financial services	1,462		12		908		198		2,370		210
Information technology	1,947		29		—		—		1,947		29
Healthcare	3,585		85		—		—		3,585		85
Consumer staples	2,427		125		—		—		2,427		125
Consumer discretionary	1,637		163		—		—		1,637		163
Energy	1,621		33		1,188		45		2,809		78
Industrials	779		18		—		—		779		18
Other	1,472		32		—		—		1,472		32
Non-redeemable preferred stocks	3,356		44		1,877		123		5,233		167
Total equity securities	18,286		541		3,973		366		22,259		907
Total temporarily impaired securities	$	422,453	$	16,670	$	36,223	$	6,548	$	458,676	$	23,218

December 31, 2015	Less than twelve months				Twelve months or longer				Total
($ in thousands)	Fair values		Unrealized losses		Fair values		Unrealized losses		Fair values		Unrealized losses
Fixed maturity securities:
U.S. government-sponsored agencies	$	78,800	$	1,228	$	34,079	$	409	$	112,879	$	1,637
Commercial mortgage-backed	6,807		17		—		—		6,807		17
Residential mortgage-backed	22,028		1,694		22,781		5,101		44,809		6,795
Other asset-backed	6,013		39		—		—		6,013		39
Corporate	101,088		2,683		14,212		906		115,300		3,589
Total fixed maturity securities	214,736		5,661		71,072		6,416		285,808		12,077
Equity securities:
Common stocks:
Financial services	6,387		333		—		—		6,387		333
Information technology	1,316		132		—		—		1,316		132
Healthcare	3,199		64		—		—		3,199		64
Consumer staples	1,244		26		—		—		1,244		26
Consumer discretionary	176		5		—		—		176		5
Energy	8,233		1,272		116		16		8,349		1,288
Industrials	1,263		11		—		—		1,263		11
Other	4,064		235		—		—		4,064		235
Non-redeemable preferred stocks	2,450		53		1,855		145		4,305		198
Total equity securities	28,332		2,131		1,971		161		30,303		2,292
Total temporarily impaired securities	$	243,068	$	7,792	$	73,043	$	6,577	$	316,111	$	14,369

Amortized cost and estimated fair value of fixed maturity securities

The amortized cost and estimated fair values of fixed maturity securities at December 31, 2016, by contractual maturity, are shown below.  Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations, with or without call or prepayment penalties.

($ in thousands)	Amortized cost		Estimated fair value
Securities available-for-sale:
Due in one year or less	$	45,253	$	45,945
Due after one year through five years	153,990		160,471
Due after five years through ten years	339,635		344,243
Due after ten years	507,687		512,355
Securities not due at a single maturity date	142,960		136,685
Totals	$	1,189,525	$	1,199,699

Summary of realized investment gains and (losses)

A summary of realized investment gains and (losses) is as follows:

	Year ended December 31,
($ in thousands)	2016			2015			2014
Fixed maturity securities available-for-sale:
Gross realized investment gains	$	2,054		$	725		$	979
Gross realized investment losses	(2,829		)	(251		)	(92		)
"Other-than-temporary" impairments	—			—			(1		)
Equity securities available-for-sale:
Gross realized investment gains	15,078			12,741			8,913
Gross realized investment losses	(2,675		)	(4,110		)	(1,727		)
"Other-than-temporary" impairments	(1,055		)	(1,481		)	(877		)
Other long-term investments, net	(6,499		)	(1,471		)	(2,846		)
Totals	$	4,074		$	6,153		$	4,349

Summary of net investment income

A summary of net investment income is as follows:

	Year ended December 31,
($ in thousands)	2016			2015			2014
Interest on fixed maturity securities	$	41,499		$	42,261		$	41,932
Dividends on equity securities	6,922			5,617			6,007
Income on reverse repurchase agreements	236			117			—
Interest on short-term investments	121			2			—
Return on long-term investments	514			(461		)	297
Total investment income	49,292			47,536			48,236
Securities litigation income	111			32			107
Investment expenses	(1,913		)	(1,986		)	(1,878		)
Net investment income	$	47,490		$	45,582		$	46,465

Summary of net changes in unrealized holding gains (losses) on securities available-for-sale

A summary of net changes in unrealized holding gains (losses) on securities available-for-sale is as follows:

	Year ended December 31,
($ in thousands)	2016			2015			2014
Fixed maturity securities	$	(20,634	)	$	(16,685	)	$	29,081
Deferred income tax expense (benefit)	(7,222		)	(5,840		)	10,179
Total fixed maturity securities	(13,412		)	(10,845		)	18,902
Equity securities	4,293			(10,997		)	17,051
Deferred income tax expense (benefit)	1,502			(3,849		)	5,967
Total equity securities	2,791			(7,148		)	11,084
Total available-for-sale securities	$	(10,621	)	$	(17,993	)	$	29,986