Investments (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Amortized cost and estimated fair value of available-for-sale fixed maturities and equity securities

Available-for-sale securities at December 31, 2015 and December 31, 2014 included the following:

	December 31, 2015
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Fixed maturities
U.S. Treasury obligations	$	122,855	$	1,696	$	659	$	123,892
U.S. Government-sponsored enterprise obligations	25,456		927		49		26,334
State and municipal bonds	904,719		36,739		823		940,635
Corporate debt	1,296,128		24,720		29,162		1,291,686
Residential mortgage-backed securities	233,659		6,039		1,311		238,387
Agency commercial mortgage-backed securities	10,851		174		26		10,999
Other commercial mortgage-backed securities	29,983		354		203		30,134
Other asset-backed securities	98,412		54		246		98,220
	$	2,722,063	$	70,703	$	32,479	$	2,760,287
	December 31, 2014
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Fixed maturities
U.S. Treasury obligations	$	163,714	$	3,785	$	987	$	166,512
U.S. Government-sponsored enterprise obligations	38,022		1,641		100		39,563
State and municipal bonds	1,015,555		47,395		335		1,062,615
Corporate debt	1,389,970		44,234		17,103		1,417,101
Residential mortgage-backed securities	266,306		10,198		448		276,056
Agency commercial mortgage-backed securities	15,344		208		59		15,493
Other commercial mortgage-backed securities	50,025		1,137		99		51,063
Other asset-backed securities	116,541		288		205		116,624
	$	3,055,477	$	108,886	$	19,336	$	3,145,027

Schedule of available for sale securities by contractual maturity

The recorded cost basis and estimated fair value of available-for-sale fixed maturities at December 31, 2015, by contractual maturity, are shown below. Actual 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		Due in one year or less		Due after one year through five years		Due after five years through ten years		Due after ten years		Total Fair Value
Fixed maturities, available for sale
U.S. Treasury obligations	$	122,855	$	10,703	$	94,067	$	15,923	$	3,199	$	123,892
U.S. Government-sponsored enterprise obligations	25,456		2,290		16,593		7,312		139		26,334
State and municipal bonds	904,719		48,752		332,489		428,872		130,522		940,635
Corporate debt	1,296,128		104,746		698,148		455,849		32,943		1,291,686
Residential mortgage-backed securities	233,659										238,387
Agency commercial mortgage-backed securities	10,851										10,999
Other commercial mortgage-backed securities	29,983										30,134
Other asset-backed securities	98,412										98,220
	$	2,722,063									$	2,760,287

Other Investments

Other investments at December 31, 2015 and December 31, 2014 were comprised as follows:

(In thousands)	December 31, 2015		December 31, 2014
Investments in LPs/LLCs, at cost	$	44,958	$	53,258
Convertible securities, at fair value	30,611		28,958
Other, principally FHLB capital stock, at cost	3,564		3,841
	$	79,133	$	86,057

Unconsolidated Subsidiaries

ProAssurance holds investments in unconsolidated subsidiaries, accounted for under the equity method. The investments include the following:

	December 31, 2015	Carrying Value
(In thousands)	Percentage Ownership	December 31, 2015		December 31, 2014
Investment in LPs/LLCs:
Qualified affordable housing tax credit partnerships	See below	$	121,550	$	133,143
Other tax credit partnerships	See below	8,362		—
All other LPs/LLCs	See below	181,996		143,358
		$	311,908	$	276,501

Investments held in an unrealized loss position

The following tables provide summarized information with respect to investments held in an unrealized loss position at December 31, 2015 and December 31, 2014, including the length of time the investment had been held in a continuous unrealized loss position.

	December 31, 2015
	Total				Less than 12 months				12 months or longer
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(In thousands)	Value		Loss		Value		Loss		Value		Loss
Fixed maturities, available for sale
U.S. Treasury obligations	$	66,685	$	658	$	61,869	$	591	$	4,816	$	67
U.S. Government-sponsored enterprise obligations	6,819		49		6,819		49		—		—
State and municipal bonds	46,193		823		36,822		703		9,371		120
Corporate debt	622,991		29,162		555,097		15,691		67,894		13,471
Residential mortgage-backed securities	87,567		1,311		78,961		1,095		8,606		216
Agency commercial mortgage-backed securities	409		26		—		—		409		26
Other commercial mortgage-backed securities	15,960		203		12,635		170		3,325		33
Other asset-backed securities	79,637		247		74,150		237		5,487		10
	$	926,261	$	32,479	$	826,353	$	18,536	$	99,908	$	13,943

	December 31, 2014
	Total				Less than 12 months				12 months or longer
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(In thousands)	Value		Loss		Value		Loss		Value		Loss
Fixed maturities, available for sale
U.S. Treasury obligations	$	61,209	$	987	$	46,869	$	617	$	14,340	$	370
U.S. Government-sponsored enterprise obligations	6,268		100		2,775		44		3,493		56
State and municipal bonds	39,831		335		18,910		84		20,921		251
Corporate debt	423,107		17,103		326,804		13,236		96,303		3,867
Residential mortgage-backed securities	45,006		448		14,406		31		30,600		417
Agency commercial mortgage-backed securities	4,783		59		70		—		4,713		59
Other commercial mortgage-backed securities	13,860		99		7,005		28		6,855		71
Other asset-backed securities	62,577		205		59,176		109		3,401		96
	$	656,641	$	19,336	$	476,015	$	14,149	$	180,626	$	5,187
Other investments
Investments in LPs/LLCs carried at cost	$	23,683	$	3,948	$	22,265	$	3,711	$	1,418	$	237

Net Investment Income

Net investment income by investment category was as follows:

	Year Ended December 31
(In thousands)	2015			2014			2013
Fixed maturities	$	97,348		$	111,895		$	122,065
Equities	13,317			10,817			9,454
Short-term and Other investments	2,049			8,833			2,584
BOLI	2,053			2,006			1,960
Investment fees and expenses	(6,107		)	(7,994		)	(6,798		)
Net investment income	$	108,660		$	125,557		$	129,265

Net realized investment gains (losses)

The following table provides detailed information regarding net realized investment gains (losses):

	Year Ended December 31
(In thousands)	2015			2014			2013
Total OTTI losses:
State and municipal bonds	$	—		$	(50	)	$	(71	)
Corporate debt	(11,781		)	(1,425		)	—
Other investments	(8,136		)	—			—
Portion recognized in OCI:
Corporate debt	4,572			268			—
Net impairments recognized in earnings	(15,345		)	(1,207		)	(71		)
Gross realized gains, available-for-sale securities	11,936			5,627			18,130
Gross realized (losses), available-for-sale securities	(11,481		)	(1,103		)	(7,031		)
Net realized gains (losses), trading securities	1,080			28,018			20,444
Net realized gains (losses), Other investments	464			326			—
Change in unrealized holding gains (losses), trading securities	(28,343		)	(18,883		)	35,507
Change in unrealized holding gains (losses), convertible securities, carried at fair value	(896		)	1,876			—
Other	946			—			925
Net realized investment gains (losses)	$	(41,639	)	$	14,654		$	67,904

Cumulative credit losses recorded in earnings related to impaired debt securities for which a portion of the OTTI has been recorded in OCI

The following table presents a roll forward of cumulative credit losses recorded in earnings related to impaired debt securities for which a portion of the OTTI was recorded in OCI.

(In thousands)	2015			2014		2013
Balance January 1	$	232		$	83	$	3,301
Additional credit losses recognized during the period, related to securities for which:
No OTTI has been previously recognized	3,648			149		—
OTTI has been previously recognized	2,645			—		—
Reductions due to:
Securities sold during the period (realized)	(774		)	—		(3,218		)
Balance December 31	$	5,751		$	232	$	83

Information regarding sales and purchases of available-for-sale securities

Other information regarding sales and purchases of available-for-sale securities is as follows:

	Year Ended December 31
(In millions)	2015		2014		2013
Proceeds from sales (exclusive of maturities and paydowns)	$	481.8	$	244.9	$	593.3
Purchases	$	580.6	$	645.1	$	519.2