Investments (Table Text Block)

12 Months Ended

Mar. 31, 2019

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Available-for-Sale Investments

		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses More than 12 Months		Gross Unrealized Losses Less than 12 Months		Estimated Market Value
		(In thousands)
U.S. treasury securities and government obligations	$	136,010	$	2,409	$	(2,104)	$	(447)	$	135,868
U.S. government agency mortgage-backed securities		31,101		433		(146)		(19)		31,369
Obligations of states and political subdivisions		298,955		8,079		(233)		(905)		305,896
Corporate securities		1,613,199		14,777		(14,257)		(24,986)		1,588,733
Mortgage-backed securities		148,203		880		(285)		(903)		147,895
Redeemable preferred stocks		1,493		20		–		(45)		1,468
	$	2,228,961	$	26,598	$	(17,025)	$	(27,305)	$	2,211,229

		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses More than 12 Months		Gross Unrealized Losses Less than 12 Months		Estimated Market Value
		(In thousands)
U.S. treasury securities and government obligations	$	123,557	$	3,595	$	(1,036)	$	(203)	$	125,913
U.S. government agency mortgage-backed securities		15,941		572		–		(93)		16,420
Obligations of states and political subdivisions		178,702		9,938		(217)		(18)		188,405
Corporate securities		1,388,300		50,056		(3,009)		(1,826)		1,433,521
Mortgage-backed securities		114,581		2,451		(1)		(153)		116,878
Redeemable preferred stocks		2,118		129		–		–		2,247
	$	1,823,199	$	66,741	$	(4,263)	$	(2,293)	$	1,883,384

Adjusted Cost and Estimated Market Value of Available-for-sale Investments

		March 31, 2019				March 31, 2018
		Amortized Cost		Estimated Market Value		Amortized Cost		Estimated Market Value
		(In thousands)
Due in one year or less	$	71,987	$	71,954	$	36,446	$	36,674
Due after one year through five years		541,195		540,658		441,159		450,749
Due after five years through ten years		621,031		614,485		607,075		625,282
Due after ten years		845,052		834,769		621,820		651,554
		2,079,265		2,061,866		1,706,500		1,764,259
Mortgage backed securities		148,203		147,895		114,581		116,878
Redeemable preferred stocks		1,493		1,468		2,118		2,247
	$	2,228,961	$	2,211,229	$	1,823,199	$	1,883,384

Available for sale equity investments

		March 31, 2019				March 31, 2018
		Amortized Cost		Estimated Market Value		Amortized Cost		Estimated Market Value
		(In thousands)
Common stocks	$	10,123	$	17,379	$	15,732	$	27,862
Non-redeemable preferred stocks		7,451		6,789		8,491		8,614
	$	17,574	$	24,168	$	24,223	$	36,476

Carrying Value of Other Investments

		March 31,
		2019		2018
		(In thousands)
Mortgage loans, net	$	225,829	$	309,952
Short-term investments		5,546		10,350
Real estate		53,519		53,776
Policy loans		10,491		17,677
Other equity investments		5,351		7,309
	$	300,736	$	399,064