Investments (Tables)

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

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

Available-for-sale fixed maturities at March 31, 2018 and December 31, 2017 included the following:

	March 31, 2018
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Fixed maturities, available for sale
U.S. Treasury obligations	$	131,655	$	305	$	2,209	$	129,751
U.S. Government-sponsored enterprise obligations	30,377		27		445		29,959
State and municipal bonds	324,336		6,613		954		329,995
Corporate debt	1,259,132		7,008		17,877		1,248,263
Residential mortgage-backed securities	217,891		1,502		3,973		215,420
Agency commercial mortgage-backed securities	15,078		29		220		14,887
Other commercial mortgage-backed securities	29,409		100		314		29,195
Other asset-backed securities	157,506		40		1,333		156,213
	$	2,165,384	$	15,624	$	27,325	$	2,153,683
	December 31, 2017
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Fixed maturities, available for sale
U.S. Treasury obligations	$	134,323	$	485	$	1,181	$	133,627
U.S. Government-sponsored enterprise obligations	21,089		73		206		20,956
State and municipal bonds	618,414		14,248		419		632,243
Corporate debt	1,157,660		15,205		5,707		1,167,158
Residential mortgage-backed securities	196,741		2,438		1,335		197,844
Agency commercial mortgage-backed securities	10,827		23		108		10,742
Other commercial mortgage-backed securities	16,004		91		134		15,961
Other asset-backed securities	102,130		47		466		101,711
	$	2,257,188	$	32,610	$	9,556	$	2,280,242

Schedule of available for sale securities by contractual maturity

The recorded cost basis and estimated fair value of available-for-sale fixed maturities at March 31, 2018, 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	$	131,655	$	31,700	$	73,858	$	21,321	$	2,872	$	129,751
U.S. Government-sponsored enterprise obligations	30,377		—		8,009		21,814		136		29,959
State and municipal bonds	324,336		29,481		111,512		140,004		48,998		329,995
Corporate debt	1,259,132		115,385		682,646		404,159		46,073		1,248,263
Residential mortgage-backed securities	217,891										215,420
Agency commercial mortgage-backed securities	15,078										14,887
Other commercial mortgage-backed securities	29,409										29,195
Other asset-backed securities	157,506										156,213
	$	2,165,384									$	2,153,683

Investments held in an unrealized loss position

The following tables provide summarized information with respect to investments held in an unrealized loss position at March 31, 2018 and December 31, 2017, including the length of time the investment had been held in a continuous unrealized loss position.

	March 31, 2018
	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	$	121,718	$	2,209	$	87,740	$	1,438	$	33,978	$	771
U.S. Government-sponsored enterprise obligations	29,018		445		22,252		218		6,766		227
State and municipal bonds	63,690		954		55,761		620		7,929		334
Corporate debt	848,499		17,877		733,344		13,216		115,155		4,661
Residential mortgage-backed securities	175,295		3,973		132,075		2,066		43,220		1,907
Agency commercial mortgage-backed securities	9,547		220		7,638		101		1,909		119
Other commercial mortgage-backed securities	19,145		314		15,723		256		3,422		58
Other asset-backed securities	118,780		1,333		105,370		1,134		13,410		199
	$	1,385,692	$	27,325	$	1,159,903	$	19,049	$	225,789	$	8,276

	December 31, 2017
	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	$	110,788	$	1,181	$	67,135	$	554	$	43,653	$	627
U.S. Government-sponsored enterprise obligations	17,032		206		10,182		64		6,850		142
State and municipal bonds	23,122		419		15,168		102		7,954		317
Corporate debt	487,578		5,707		365,541		2,730		122,037		2,977
Residential mortgage-backed securities	109,659		1,335		64,121		402		45,538		933
Agency commercial mortgage-backed securities	4,423		108		2,458		34		1,965		74
Other commercial mortgage-backed securities	12,878		134		7,939		82		4,939		52
Other asset-backed securities	85,358		466		70,924		346		14,434		120
	$	850,838	$	9,556	$	603,468	$	4,314	$	247,370	$	5,242

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

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

	Three Months Ended March 31
(In millions)	2018		2017
Proceeds from sales (exclusive of maturities and paydowns)	$	379.2	$	79.2
Purchases	$	367.9	$	160.4

Net Investment Income

Net investment income by investment category was as follows:

	Three Months Ended March 31
(In thousands)	2018			2017
Fixed maturities	$	17,080		$	20,121
Equities	4,867			3,644
Short-term investments, including Other	1,308			801
BOLI	449			455
Investment fees and expenses	(1,677		)	(1,835		)
Net investment income	$	22,027		$	23,186

Investments in unconsolidated subsidiaries

ProAssurance's investment in unconsolidated subsidiaries were as follows:

	March 31, 2018	Carrying Value
(In thousands)	Percentage Ownership	March 31, 2018		December 31, 2017
Qualified affordable housing project tax credit partnerships	See below	$	80,507	$	84,607
Other tax credit partnerships	See below	5,735		6,118
All other investments, primarily investment fund LPs/LLCs	See below	314,788		239,866
		$	401,030	$	330,591

Net realized investment gains (losses)

Realized investment gains and losses are recognized on the first-in, first-out basis. The following table provides detailed information regarding net realized investment gains (losses):

	Three Months Ended March 31
(In thousands)	2018			2017
Total OTTI losses:
Corporate debt	$	—		$	(419	)
Portion of OTTI losses recognized in other comprehensive income before taxes:
Corporate debt	—			248
Net impairment losses recognized in earnings	—			(171		)
Gross realized gains, available-for-sale fixed maturities	4,464			1,853
Gross realized (losses), available-for-sale fixed maturities	(2,047		)	(67		)
Net realized gains (losses), equity investments	9,219			6,562
Net realized gains (losses), other investments	688			1,172
Change in unrealized holding gains (losses), trading fixed maturities	(49		)	—
Change in unrealized holding gains (losses), equity investments	(23,845		)	3,616
Change in unrealized holding gains (losses), convertible securities, carried at fair value	(954		)	313
Other	7			2
Net realized investment gains (losses)	$	(12,517	)	$	13,280

Other than temporary impairment, credit losses recognized in earnings

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.

	Three Months Ended March 31
(In thousands)	2018		2017
Balance beginning of period	$	1,313	$	1,158
Additional credit losses recognized during the period, related to securities for which:
No OTTI has been previously recognized	—		171
Balance March 31	$	1,313	$	1,329