Investments (Table Text Block)

3 Months Ended

Jun. 30, 2018

Mar. 31, 2018

Investments Debt Equity Securities [Abstract]

Available-for-Sale Investments

Available-for-sale investments at June 30, 2018 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	$	123,420	$	1,858	$	(1,561)	$	(911)	$	122,806
U.S. government agency mortgage-backed securities		63,031		714		(1)		(662)		63,082
Obligations of states and political subdivisions		190,454		7,481		(236)		(538)		197,161
Corporate securities		1,423,091		26,369		(5,291)		(15,275)		1,428,894
Mortgage-backed securities		101,605		1,055		–		(765)		101,895
Redeemable preferred stocks		2,118		93		_		_		2,211
	$	1,903,719	$	37,570	$	(7,089)	$	(18,151)	$	1,916,049

Available-for-sale investments at March 31, 2018 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	$	123,557	$	3,595	$	(1,036)	$	(203)	$	125,913
U.S. government agency mortgage-backed securities		36,416		951		(1)		(93)		37,273
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		94,106		2,072		–		(153)		96,025
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

		June 30, 2018				March 31, 2018
		Amortized Cost		Estimated Market Value		Amortized Cost		Estimated Market Value
		(Unaudited)
		(In thousands)
Due in one year or less	$	42,372	$	42,546	$	36,446	$	36,674
Due after one year through five years		469,929		472,652		441,223		450,816
Due after five years through ten years		616,785		618,194		607,895		626,174
Due after ten years		670,910		678,551		641,411		671,448
		1,799,996		1,811,943		1,726,975		1,785,112
Mortgage backed securities		101,605		101,895		94,106		96,025
Redeemable preferred stocks		2,118		2,211		2,118		2,247
	$	1,903,719	$	1,916,049	$	1,823,199	$	1,883,384