Investments in Marketable Debt Securities

12 Months Ended

Dec. 31, 2019

Available For Sale Securities [Abstract]

Investments in Marketable Debt Securities

C. INVESTMENTS IN MARKETABLE DEBT SECURITIES

Marketable debt securities consisted of the following at December 31:

	AMORTIZED		UNREALIZED		UNREALIZED		FAIR
2019	COST		GAINS		LOSSES		VALUE
U.S. tax-exempt securities	$	318.1	$	2.2	$	.1	$	320.2
U.S. corporate securities		163.8		1.9				165.7
U.S. government and agency securities		128.4		.9				129.3
Non-U.S. corporate securities		347.7		2.3		.2		349.8
Non-U.S. government securities		72.3		.2		.1		72.4
Other debt securities		123.7		1.1		.1		124.7
	$	1,154.0	$	8.6	$	.5	$	1,162.1

	AMORTIZED		UNREALIZED		UNREALIZED		FAIR
2018	COST		GAINS		LOSSES		VALUE
U.S. tax-exempt securities	$	326.0	$	.3	$	1.2	$	325.1
U.S. corporate securities		147.6		.2		.4		147.4
U.S. government and agency securities		98.9		.2		.4		98.7
Non-U.S. corporate securities		272.5		.4		1.6		271.3
Non-U.S. government securities		55.9		.1		.1		55.9
Other debt securities		122.6		.2		.8		122.0
	$	1,023.5	$	1.4	$	4.5	$	1,020.4

The cost of marketable debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Amortization, accretion, interest and dividend income and realized gains and losses are included in investment income. The cost of securities sold is based on the specific identification method. Gross realized gains were $1.3, $1.1 and $1.4, and gross realized losses were $.4, $.8 and $.5 for the years ended December 31, 2019, 2018 and 2017, respectively.

Marketable debt securities with continuous unrealized losses and their related fair values were as follows:

At December 31,	2019				2018
	LESS THAN TWELVE MONTHS		TWELVE MONTHS OR GREATER		LESS THAN TWELVE MONTHS		TWELVE MONTHS OR GREATER
Fair value	$	177.0	$	31.4	$	252.8	$	397.9
Unrealized losses		.4		.1		.8		3.7

For the investment securities in gross unrealized loss positions identified above, the Company does not intend to sell the investment securities. It is more likely than not that the Company will not be required to sell the investment securities before recovery of the unrealized losses, and the Company expects that the contractual principal and interest will be received on the investment securities. As a result, the Company recognized no other-than-temporary impairments during the periods presented.

Contractual maturities on marketable debt securities at December 31, 2019 were as follows:

	AMORTIZED		FAIR
Maturities:	COST		VALUE
Within one year	$	291.6	$	292.1
One to five years		806.4		813.9
Six to ten years		24.0		24.1
More than ten years		32.0		32.0
	$	1,154.0	$	1,162.1

Marketable debt securities included $49.7 and $7.4 of variable rate demand obligations (VRDOs) at December 31, 2019 and 2018, respectively. VRDOs are debt instruments with long-term scheduled maturities which have interest rates that reset periodically. Actual maturities of VRDOs may differ from contractual maturities because these securities may be sold when interest rates are reset.