Investments (Tables)

12 Months Ended

Dec. 31, 2014

Investments [Abstract]

Schedule of trading securities

Securities accounted for at fair value with changes in fair value recognized in the consolidated income statements by category are as follows:

	December 31, 2014				December 31, 2013
	Fair Value		Amortized Cost		Fair Value		Amortized Cost
U.S. government and government agencies	$	1,610,502	$	1,610,880	$	1,676,788	$	1,684,832
Non-U.S. government and government agencies	188,199		196,332		191,776		197,082
States, municipalities and political subdivisions	170,567		165,615		231,555		234,406
Corporate debt:
Financial institutions	1,024,667		1,018,777		958,794		943,518
Industrials	1,029,729		1,037,820		1,174,047		1,165,448
Utilities	110,997		111,599		69,426		69,658
Mortgage-backed	1,263,517		1,219,712		1,292,502		1,267,863
Asset-backed	670,832		674,505		505,910		502,543
Total fixed maturity investments, trading	$	6,069,010	$	6,035,240	$	6,100,798	$	6,065,350

	December 31, 2014				December 31, 2013
	Fair Value		Cost		Fair Value		Cost
Equity securities	$	844,163	$	791,206	$	699,846	$	647,301
Other invested assets	812,543		725,069		764,081		658,683
	$	1,656,706	$	1,516,275	$	1,463,927	$	1,305,984

Schedule of other invested assets

Details regarding the carrying value, redemption characteristics and unfunded investment commitments of the other invested assets portfolio as of December 31, 2014 and 2013 were as follows:

Fund Type	Carrying Value as of December 31, 2014		Investments with Redemption Restrictions		Estimated Remaining Restriction Period	Investments without Redemption Restrictions		Redemption Frequency(1)	Redemption Notice Period(1)	Unfunded Commitments
Private equity (primary and secondary)	$	184,576	$	184,576	2 - 8 Years	$	—			$	223,802
Mezzanine debt	166,905		166,905		5 - 9 Years	—				204,232
Distressed	5,869		5,869		3 Years	—				5,180
Real estate	—		—		9 Years	—				50,000
Total private equity	357,350		357,350			—				483,214
Distressed	170,169		170,169			—		Based on net asset value	60 Days	—
Equity long/short	84,198		—			84,198		Quarterly	30 -60 Days	—
Multi-strategy	51,507		—			51,507		Quarterly	45 -90 Days	—
Relative value credit	119,156		—			119,156		Quarterly	60 Days	—
Total hedge funds	425,030		170,169			254,861				—
High yield loan fund	30,163		—			30,163		Monthly	30 days	—
Total other invested assets at fair value	812,543		527,519			285,024				483,214
Other private securities	142,966		—			142,966				—
Total other invested assets	$	955,509	$	527,519		$	427,990			$	483,214

Fund Type	Carrying Value as of December 31, 2013		Investments with Redemption Restrictions		Estimated Remaining Restriction Period	Investments without Redemption Restrictions		Redemption Frequency(1)	Redemption Notice Period(1)	Unfunded Commitments
Private equity (primary and secondary)	$	144,422	$	144,422	2 - 9 Years	$	—			$	263,519
Mezzanine debt	64,627		64,627		8 - 9 Years	—				198,756
Distressed	7,776		7,776		4 Years	—				5,249
Total private equity	216,825		216,825			—				467,524
Distressed	151,227		151,227		1 - 2 Years	—				—
Equity long/short	99,365		—			99,365		Quarterly	30 -60 Days	—
Multi-strategy	136,958		—			136,958		Quarterly	45 -90 Days	—
Event driven	14,018		—			14,018		Annual	60 Days	—
Relative value credit	113,730		—			113,730		Quarterly	60 Days	—
Total hedge funds	515,298		151,227			364,071				—
High yield loan fund	31,958		—			31,958		Monthly	30 days	—
Total other invested assets at fair value	764,081		368,052			396,029				467,524
Other private securities	147,311		—			147,311				—
Total other invested assets	$	911,392	$	368,052		$	543,340			$	467,524

(1) The redemption frequency and notice periods only apply to the investments without redemption restrictions.

Schedule of net investment income

	Year Ended December 31,
	2014			2013			2012
Fixed maturity investments	$	149,449		$	130,380		$	157,437
Equity securities	17,581			19,076			17,080
Other invested assets: hedge funds and private equity	12,564			8,226			6,772
Other invested assets: other private securities	13,305			14,711			—
Cash and cash equivalents	2,134			2,010			2,319
Expenses	(18,159		)	(16,839		)	(16,467		)
Net investment income	$	176,874		$	157,564		$	167,141

Components of realized gains and losses

	Year Ended December 31,
	2014			2013			2012
Gross realized gains on sale of invested assets	$	195,390		$	213,618		$	183,592
Gross realized losses on sale of invested assets	(48,239		)	(106,321		)	(51,702		)
Net realized and unrealized gains (losses) on derivatives	(39,007		)	9,485			(3,608		)
Mark-to-market gains (losses):
Debt securities, trading	(1,675		)	(117,577		)	106,328
Equity securities, trading	413			4,288			33,018
Other invested assets, trading	(17,925		)	56,032			38,808
Net realized investment gains	$	88,957		$	59,525		$	306,436
Proceeds from sale of available for sale securities	$	—		$	—		$	236,336