Investments (Tables)

6 Months Ended

Jun. 30, 2015

Amortized Cost or Cost and Fair Value of Available For Sale Securities

The amortized cost or cost and the fair value of AFS securities as of June 30, 2015 and December 31, 2014 are summarized as follows:

	Amortized Cost or Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in millions)
As of June 30, 2015
Equity securities:
Common stock	$	2,701.3	$	482.2	$	(39.9	)	$	3,143.6
Preferred stock		—		—		—			—
Total equity securities		2,701.3		482.2		(39.9	)		3,143.6
Debt securities:
U.S. Government obligations		790.7		2.4		(11.6	)		781.5
Municipal bonds		4,913.5		96.1		(28.1	)		4,981.5
Foreign government obligations		885.1		17.3		(2.0	)		900.4
U.S. corporate bonds		2,139.1		28.6		(26.5	)		2,141.2
Foreign corporate bonds		1,417.2		30.4		(10.8	)		1,436.8
Mortgage and asset-backed securities:
RMBS		1,611.0		13.5		(19.3	)		1,605.2
CMBS		1,159.1		15.0		(5.3	)		1,168.8
Other asset-backed securities(1)		1,549.6		5.1		(5.2	)		1,549.5
Total debt securities		14,465.3		208.4		(108.8	)		14,564.9
Short-term investments		601.5		—		—			601.5
Total	$	17,768.1	$	690.6	$	(148.7	)	$	18,310.0

	Amortized Cost or Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in millions)
As of December 31, 2014
Equity securities:
Common stock	$	2,366.0	$	530.3	$	(80.8	)	$	2,815.5
Preferred stock		—		—		—			—
Total equity securities		2,366.0		530.3		(80.8	)		2,815.5
Debt securities:
U.S. Government obligations		541.2		3.4		(3.5	)		541.1
Municipal bonds		5,067.3		139.3		(9.1	)		5,197.5
Foreign government obligations		876.7		23.7		—			900.4
U.S. corporate bonds		2,136.5		39.5		(21.2	)		2,154.8
Foreign corporate bonds		1,460.5		47.7		(4.5	)		1,503.7
Mortgage and asset-backed securities:
RMBS		1,646.9		20.7		(11.7	)		1,655.9
CMBS		1,104.2		22.5		(1.4	)		1,125.3
Other asset-backed securities(1)		1,531.2		2.2		(13.5	)		1,519.9
Total debt securities		14,364.5		299.0		(64.9	)		14,598.6
Short-term investments		715.6		—		—			715.6
Total	$	17,446.1	$	829.3	$	(145.7	)	$	18,129.7

(1) Includes $935.6 million and $900.7 million of collateralized loan obligations as of June 30, 2015 and December 31, 2014, respectively.

Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity

The amortized cost and estimated fair value of debt securities as of June 30, 2015 by contractual maturity are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

	Amortized Cost or Cost		Fair Value
	(in millions)
Short-term investments due in one year or less	$	601.5	$	601.5
Mortgage and asset-backed securities(1)		4,319.7		4,323.5
Debt securities with maturity dates:
One year or less		553.2		556.6
Over one through five years		3,131.3		3,160.3
Over five through ten years		2,975.6		3,002.1
Over ten years		3,485.5		3,522.4
Total debt securities		14,465.3		14,564.9
Equity securities		2,701.3		3,143.6
Total	$	17,768.1	$	18,310.0

(1) Mortgage and asset-backed securities by their nature do not generally have single maturity dates.

Net Investment Income

Net investment income for the three and six months ended June 30, 2015 and 2014 were as follows:

	Three Months Ended June 30,						Six Months Ended June 30,
	2015			2014			2015			2014
	(in millions)
Interest income	$	92.5		$	97.4		$	187.2		$	192.7
Dividend income		11.9			19.8			26.4			33.3
Investment expenses		(6.1	)		(7.4	)		(13.3	)		(14.4	)
Equity in results of Pillar Investments(1)		1.0			3.6			7.6			7.5
Equity in results of Ares(1)		3.3			3.0			5.6			3.1
Equity in results of ORX		(3.7	)		(1.1	)		(4.7	)		(0.7	)
Other investment results		4.2			(1.2	)		7.7			3.2
Total	$	103.1		$	114.1		$	216.5		$	224.7

(1) See Note 3(g) for discussion of the Pillar Investments as defined therein and the investment in Ares.

Amount of Gross Realized Capital Gains and Gross Realized Capital Losses of Available For Sale Securities

The amounts of gross realized capital gains and gross realized capital losses for the three and six months ended June 30, 2015 and 2014 were as follows:

	Three Months Ended June 30,						Six Months Ended June 30,
	2015			2014			2015			2014
	(in millions)
Gross realized capital gains	$	101.7		$	46.2		$	216.1		$	153.9
Gross realized capital losses		(15.5	)		(4.7	)		(86.8	)		(15.5	)
Net realized capital gains	$	86.2		$	41.5		$	129.3		$	138.4

Gross Unrealized Losses and Related Fair Values for Debt Securities and Equity Securities Grouped by Duration of Time in Continuous Unrealized Loss Position

As of June 30, 2015 and December 31, 2014, gross unrealized losses and related fair values for equity securities and debt securities, grouped by duration of time in a continuous unrealized loss position, were as follows:

	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(in millions)
As of June 30, 2015
Equity securities:
Common stock	$	705.4	$	39.9	$	—	$	—	$	705.4	$	39.9
Preferred stock		—		—		—		—		—		—
Total equity securities		705.4		39.9		—		—		705.4		39.9
Debt securities:
U.S. Government obligations		366.3		11.5		8.2		0.1		374.5		11.6
Municipal bonds		1,317.1		22.9		97.7		5.2		1,414.8		28.1
Foreign government obligations		218.2		2.0		—		—		218.2		2.0
U.S. corporate bonds		842.4		19.5		87.5		7.0		929.9		26.5
Foreign corporate bonds		397.2		10.4		11.4		0.4		408.6		10.8
Mortgage and asset-backed securities:
RMBS		609.4		8.5		388.8		10.8		998.2		19.3
CMBS		321.7		4.9		36.7		0.4		358.4		5.3
Other asset-backed securities		640.5		3.1		198.5		2.1		839.0		5.2
Total debt securities		4,712.8		82.8		828.8		26.0		5,541.6		108.8
Total temporarily impaired securities	$	5,418.2	$	122.7	$	828.8	$	26.0	$	6,247.0	$	148.7

	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(in millions)
As of December 31, 2014
Equity securities:
Common stock	$	514.4	$	80.8	$	—	$	—	$	514.4	$	80.8
Preferred stock		—		—		—		—		—		—
Total equity securities		514.4		80.8		—		—		514.4		80.8
Debt securities:
U.S. Government obligations		270.5		3.1		16.3		0.4		286.8		3.5
Municipal bonds		105.2		0.8		372.0		8.3		477.2		9.1
Foreign government obligations		6.1		—		5.7		—		11.8		—
U.S. corporate bonds		574.7		17.2		150.7		4.0		725.4		21.2
Foreign corporate bonds		133.4		4.1		26.2		0.4		159.6		4.5
Mortgage and asset-backed securities:
RMBS		187.9		0.5		586.4		11.2		774.3		11.7
CMBS		176.5		0.7		60.9		0.7		237.4		1.4
Other asset-backed securities		1,041.1		12.7		175.3		0.8		1,216.4		13.5
Total debt securities		2,495.4		39.1		1,393.5		25.8		3,888.9		64.9
Total temporarily impaired securities	$	3,009.8	$	119.9	$	1,393.5	$	25.8	$	4,403.3	$	145.7