Investments (Table Text Block)

3 Months Ended

12 Months Ended

Jun. 30, 2015

Mar. 31, 2015

Investments Debt Equity Securities [Abstract]

Available-for-Sale Investments

Available-for-sale investments at June 30, 2015 were as follows:

		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses More than 12 Months		Gross Unrealized Losses Less than 12 Months		Estimated Market Value
		(Unaudited)
		(In thousands)
U.S. treasury securities and government obligations	$	88,561	$	5,796	$	–	$	(33)	$	94,324
U.S. government agency mortgage-backed securities		29,224		2,712		–		(2)		31,934
Obligations of states and political subdivisions		162,859		14,467		(34)		(87)		177,205
Corporate securities		917,476		52,995		(1,489)		(1,867)		967,115
Mortgage-backed securities		19,259		994		(1)		–		20,252
Redeemable preferred stocks		18,053		591		(54)		(38)		18,552
Common stocks		18,143		6,786		–		(112)		24,817
	$	1,253,575	$	84,341	$	(1,578)	$	(2,139)	$	1,334,199

Available-for-sale investments at March 31, 2015 were as follows:

		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	$	99,722	$	5,658	$	(64)	$	–	$	105,316
U.S. government agency mortgage-backed securities		30,569		2,614		(39)		(3)		33,141
Obligations of states and political subdivisions		165,724		13,052		(298)		(10)		178,468
Corporate securities		885,470		44,426		(2,522)		(2,966)		924,408
Mortgage-backed securities		19,874		806		(1)		–		20,679
Redeemable preferred stocks		18,052		521		(253)		(24)		18,296
Common stocks		17,975		6,719		–		(40)		24,654
	$	1,237,386	$	73,796	$	(3,177)	$	(3,043)	$	1,304,962

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

		June 30, 2015				March 31, 2015
		Amortized Cost		Estimated Market Value		Amortized Cost		Estimated Market Value
		(Unaudited)
		(In thousands)
Due in one year or less	$	52,734	$	53,626	$	36,355	$	37,055
Due after one year through five years		182,786		194,033		198,488		209,404
Due after five years through ten years		494,677		519,766		474,639		492,782
Due after ten years		467,923		503,153		472,003		502,092
		1,198,120		1,270,578		1,181,485		1,241,333
Mortgage backed securities		19,259		20,252		19,874		20,679
Redeemable preferred stocks		18,053		18,552		18,052		18,296
Equity securities		18,143		24,817		17,975		24,654
	$	1,253,575	$	1,334,199	$	1,237,386	$	1,304,962