Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Disclosures [Abstract]

Balances Of Assets Measured At Fair Value On A Recurring Basis

The following tables present the balances of assets measured at fair value on a recurring basis by level within the fair value hierarchy.

	June 30, 2017
(dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Investments available-for-sale:
Fixed maturities:
U.S. Treasury securities	$	—	$	137,641	$	—	$	137,641
U.S. government-sponsored enterprises	—		381,879		—		381,879
Obligations of states, municipalities and political subdivisions	—		4,653,366		—		4,653,366
Foreign governments	—		1,451,717		—		1,451,717
Commercial mortgage-backed securities	—		1,183,399		—		1,183,399
Residential mortgage-backed securities	—		848,775		—		848,775
Asset-backed securities	—		37,797		—		37,797
Corporate bonds	—		1,358,918		—		1,358,918
Total fixed maturities	—		10,053,492		—		10,053,492
Equity securities:
Insurance, banks and other financial institutions	1,680,416		—		183,913		1,864,329
Industrial, consumer and all other	3,476,498		—		—		3,476,498
Total equity securities	5,156,914		—		183,913		5,340,827
Short-term investments	1,614,064		90,352		—		1,704,416
Total investments available-for-sale	$	6,770,978	$	10,143,844	$	183,913	$	17,098,735

	December 31, 2016
(dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Investments available-for-sale:
Fixed maturities:
U.S. Treasury securities	$	—	$	258,584	$	—	$	258,584
U.S. government-sponsored enterprises	—		423,212		—		423,212
Obligations of states, municipalities and political subdivisions	—		4,428,205		—		4,428,205
Foreign governments	—		1,463,462		—		1,463,462
Commercial mortgage-backed securities	—		1,040,356		—		1,040,356
Residential mortgage-backed securities	—		790,946		—		790,946
Asset-backed securities	—		27,338		—		27,338
Corporate bonds	—		1,459,407		—		1,459,407
Total fixed maturities	—		9,891,510		—		9,891,510
Equity securities:
Insurance, banks and other financial institutions	1,506,607		—		191,203		1,697,810
Industrial, consumer and all other	3,048,031		—		—		3,048,031
Total equity securities	4,554,638		—		191,203		4,745,841
Short-term investments	2,255,898		80,253		—		2,336,151
Total investments available-for-sale	$	6,810,536	$	9,971,763	$	191,203	$	16,973,502

Summary Of Changes In Level 3 Investments Measured At Fair Value On A Recurring Basis

The following table summarizes changes in Level 3 investments measured at fair value on a recurring basis.

	Quarter Ended June 30,						Six Months Ended June 30,
(dollars in thousands)	2017			2016			2017			2016
Equity securities, beginning of period	$	178,043		$	176,942		$	191,203		$	—
Purchases	1,250			25,000			7,250			195,250
Sales	(1,303		)	(25,000		)	(26,674		)	(25,000		)
Total gains included in:
Net income	5,923			6,581			12,134			13,273
Other comprehensive income	—			—			—			—
Transfers into Level 3	—			—			—			—
Transfers out of Level 3	—			—			—			—
Equity securities, end of period	$	183,913		$	183,523		$	183,913		$	183,523
Net unrealized gains included in net income relating to assets held at June 30, 2017 and 2016 (1)	$	5,923		$	6,581		$	12,134		$	13,273

⁽¹⁾Included in net realized investment gains in the consolidated statements of income and comprehensive income.