Fair Value Measurements - Schedule of assets and liabilities that were accounted for at fair value (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Assets
Fixed maturities, at fair value		$ 31,858,724	$ 32,257,589
Equity securities, at fair value		1,039,793	878,919
Short-term investments, at fair value		444,301	617,390
Total investments available for sale		33,342,818	33,753,898
Fixed maturities, trading at fair value		1,478,407	1,235,699
Short-term investments, trading at fair value		18,499	60,330
Total investments trading		1,496,906	1,296,029
Collateral and counterparty netting, assets	[1],[2]	(2,674)	(3,087)
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)		1,145,314	914,629
Collateral and counterparty nettings, liabilities	[1],[2]	(2,674)	(3,087)
Recurring
Assets
Total investments available for sale		33,342,818	33,753,898
Cash equivalents	[3]	1,602,577	1,268,666
Other investments	[4]	1,156,028	1,291,726
Other assets	[2]	79,135	86,227
Total assets accounted for at fair value		37,777,598	37,797,820
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[5]	900,110	463,915
Financial instruments sold, but not yet purchased	[6]	0	347
Other liabilities	[2]	49,320	42,408
Total liabilities accounted for at fair value		949,430	506,670
Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Total investments available for sale		547,218	528,581
Cash equivalents	[3]	222,533	437,742
Other investments	[4]	0	0
Other assets	[2]	0	0
Total assets accounted for at fair value		769,751	966,840
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[5]	0	0
Financial instruments sold, but not yet purchased	[6]	0	347
Other liabilities	[2]	0	0
Total liabilities accounted for at fair value		0	347
Recurring | Significant other observable inputs (Level 2)
Assets
Total investments available for sale		32,681,114	33,073,039
Cash equivalents	[3]	1,380,044	830,924
Other investments	[4]	912,790	1,008,176
Other assets	[2]	62,209	69,914
Total assets accounted for at fair value		36,633,197	36,378,839
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[5]	900,110	463,915
Financial instruments sold, but not yet purchased	[6]	0	0
Other liabilities	[2]	22,558	16,304
Total liabilities accounted for at fair value		922,668	480,219
Recurring | Significant other unobservable inputs (Level 3)
Assets
Total investments available for sale		114,486	152,278
Cash equivalents	[3]	0	0
Other investments	[4]	243,238	283,550
Other assets	[2]	19,600	19,400
Total assets accounted for at fair value		377,324	455,228
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[5]	0	0
Financial instruments sold, but not yet purchased	[6]	0	0
Other liabilities	[2]	29,436	29,191
Total liabilities accounted for at fair value		29,436	29,191
Excluding Life Funds Withheld Assets
Assets
Fixed maturities, at fair value		29,014,918	29,104,486
Equity securities, at fair value		1,039,793	878,919
Short-term investments, at fair value		444,301	617,390
Total investments available for sale		30,499,012	30,600,795
Excluding Life Funds Withheld Assets | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		4,134,088	5,065,637
Excluding Life Funds Withheld Assets | RMBS - Agency
Assets
Fixed maturities, at fair value		4,455,630	3,757,971
Excluding Life Funds Withheld Assets | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		288,815	328,540
Excluding Life Funds Withheld Assets | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		278,314	405,316
Excluding Life Funds Withheld Assets | Collateralized debt obligations
Assets
Fixed maturities, at fair value		17,800	32,410
Excluding Life Funds Withheld Assets | Other asset-backed securities
Assets
Fixed maturities, at fair value		1,043,478	1,168,572
Excluding Life Funds Withheld Assets | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		2,635,034	2,632,070
Excluding Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		5,607,431	5,251,614
Excluding Life Funds Withheld Assets | Recurring
Assets
Fixed maturities, at fair value		29,014,918	29,104,486
Equity securities, at fair value		1,039,793	878,919
Short-term investments, at fair value	[7]	444,301	617,390
Total investments available for sale		30,499,012	30,600,795
Excluding Life Funds Withheld Assets | Recurring | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		4,134,088	5,065,637
Excluding Life Funds Withheld Assets | Recurring | RMBS - Agency
Assets
Fixed maturities, at fair value		4,455,630	3,757,971
Excluding Life Funds Withheld Assets | Recurring | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		288,815	328,540
Excluding Life Funds Withheld Assets | Recurring | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		278,314	405,316
Excluding Life Funds Withheld Assets | Recurring | Collateralized debt obligations
Assets
Fixed maturities, at fair value		17,800	32,410
Excluding Life Funds Withheld Assets | Recurring | Other asset-backed securities
Assets
Fixed maturities, at fair value		1,043,478	1,168,572
Excluding Life Funds Withheld Assets | Recurring | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		2,635,034	2,632,070
Excluding Life Funds Withheld Assets | Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		5,607,431	5,251,614
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Fixed maturities, at fair value		0	0
Equity securities, at fair value		547,218	528,581
Short-term investments, at fair value	[7]	0	0
Total investments available for sale		547,218	528,581
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Agency
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Collateralized debt obligations
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Other asset-backed securities
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2)
Assets
Fixed maturities, at fair value		28,900,432	28,952,208
Equity securities, at fair value		492,575	350,338
Short-term investments, at fair value	[7]	444,301	617,390
Total investments available for sale		29,837,308	29,919,936
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		4,089,832	5,020,574
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Agency
Assets
Fixed maturities, at fair value		4,455,615	3,754,894
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		288,815	328,540
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		278,314	405,316
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Collateralized debt obligations
Assets
Fixed maturities, at fair value		6	2
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities
Assets
Fixed maturities, at fair value		1,036,623	1,150,715
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		2,635,034	2,632,070
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		5,607,431	5,251,614
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3)
Assets
Fixed maturities, at fair value		114,486	152,278
Equity securities, at fair value			0
Short-term investments, at fair value	[7]	0	0
Total investments available for sale		114,486	152,278
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		44,256	45,063
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency
Assets
Fixed maturities, at fair value		15	3,077
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Collateralized debt obligations
Assets
Fixed maturities, at fair value		17,794	32,408
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Other asset-backed securities
Assets
Fixed maturities, at fair value		6,855	17,857
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		0	0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0	0
Life Funds Withheld Assets
Assets
Fixed maturities, at fair value		2,843,806	3,153,103
Fixed maturities, trading at fair value		1,478,407	1,235,699
Short-term investments, trading at fair value		18,499	60,330
Total investments trading		1,496,906	1,296,029
Life Funds Withheld Assets | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		12,499	12,742
Fixed maturities, trading at fair value		18,570	4,990
Life Funds Withheld Assets | RMBS - Agency
Assets
Fixed maturities, at fair value		686	752
Fixed maturities, trading at fair value		1,868	368
Life Funds Withheld Assets | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		24,252	26,953
Fixed maturities, trading at fair value		197
Life Funds Withheld Assets | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		105,019	122,481
Fixed maturities, trading at fair value		5,223	4,803
Life Funds Withheld Assets | Collateralized debt obligations
Assets
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Other asset-backed securities
Assets
Fixed maturities, at fair value		117,797	149,795
Fixed maturities, trading at fair value		25,965	25,700
Life Funds Withheld Assets | US States and political subdivisions of the States
Assets
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		850,593	933,516
Fixed maturities, trading at fair value		417,411	370,261
Life Funds Withheld Assets | Recurring
Assets
Fixed maturities, at fair value		2,843,806	3,153,103
Fixed maturities, trading at fair value		1,478,407	1,235,699
Short-term investments, trading at fair value	[7]	18,499	60,330
Total investments trading		1,496,906	1,296,029
Cash equivalents	[3]	100,134	101,274
Life Funds Withheld Assets | Recurring | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		12,499	12,742
Fixed maturities, trading at fair value		18,570	4,990
Life Funds Withheld Assets | Recurring | RMBS - Agency
Assets
Fixed maturities, at fair value		686	752
Fixed maturities, trading at fair value		1,868	368
Life Funds Withheld Assets | Recurring | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		24,252	26,953
Fixed maturities, trading at fair value		197
Life Funds Withheld Assets | Recurring | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		105,019	122,481
Fixed maturities, trading at fair value		5,223	4,803
Life Funds Withheld Assets | Recurring | Other asset-backed securities
Assets
Fixed maturities, at fair value		117,797	149,795
Fixed maturities, trading at fair value		25,965	25,700
Life Funds Withheld Assets | Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		850,593	933,516
Fixed maturities, trading at fair value		417,411	370,261
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Short-term investments, trading at fair value	[7]	0	0
Total investments trading		0	0
Cash equivalents	[3]	0	517
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Agency
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Other asset-backed securities
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2)
Assets
Fixed maturities, at fair value		2,843,806	3,153,103
Fixed maturities, trading at fair value		1,478,407	1,235,699
Short-term investments, trading at fair value	[7]	18,499	60,330
Total investments trading		1,496,906	1,296,029
Cash equivalents	[3]	100,134	100,757
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		12,499	12,742
Fixed maturities, trading at fair value		18,570	4,990
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Agency
Assets
Fixed maturities, at fair value		686	752
Fixed maturities, trading at fair value		1,868	368
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		24,252	26,953
Fixed maturities, trading at fair value		197
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		105,019	122,481
Fixed maturities, trading at fair value		5,223	4,803
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities
Assets
Fixed maturities, at fair value		117,797	149,795
Fixed maturities, trading at fair value		25,965	25,700
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		850,593	933,516
Fixed maturities, trading at fair value		417,411	370,261
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3)
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Short-term investments, trading at fair value	[7]	0	0
Total investments trading		0	0
Cash equivalents	[3]	0	0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Other asset-backed securities
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Financial Services Sector | Excluding Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		3,725,971	3,561,909
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		3,725,971	3,561,909
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0	0
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		3,682,334	3,508,224
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		43,637	53,685
Financial Services Sector | Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		504,464	598,236
Fixed maturities, trading at fair value		416,325	335,956
Financial Services Sector | Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		504,464	598,236
Fixed maturities, trading at fair value		416,325	335,956
Financial Services Sector | Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		504,464	598,236
Fixed maturities, trading at fair value		416,325	335,956
Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		6,828,357	6,900,447
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		6,828,357	6,900,447
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0	0
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		6,826,428	6,900,259
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		1,929	188
Non-Financial Services Sector | Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		1,228,496	1,308,628
Fixed maturities, trading at fair value		592,848	493,621
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		1,228,496	1,308,628
Fixed maturities, trading at fair value		592,848	493,621
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		0	0
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		1,228,496	1,308,628
Fixed maturities, trading at fair value		592,848	493,621
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		0	0
Fixed maturities, trading at fair value		$ 0	$ 0

[1] Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intention to settle the contracts on a net basis. The Company often enters into different types of derivative contracts with a single counterparty and these contracts are covered under netting agreements.

[2] Other assets and other liabilities include derivative instruments. The derivative balances included in each category are reported on a gross basis by level with a netting adjustment presented separately in the Collateral and Counterparty Netting column. The fair values of the individual derivative contracts are reported gross in their respective levels based on the fair value hierarchy. For further details regarding derivative fair values and associated collateral received or paid, see Note 7, "Derivative Instruments.

[3] Cash equivalents balances subject to fair value measurement include certificates of deposit and money market funds. Operating cash balances are not subject to recurring fair value measurement guidance.

[4] The Other investments balance excludes a certain payment obligation. This investment, which totaled $141.7 million as of June 30, 2016 and $141.3 million as of December 31, 2015, is carried at amortized cost. For further information, see Item 8, Note 8, "Other Investments," to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2015.

[5] Funds withheld on GreyCastle life retrocession arrangements (net of future policy benefit reserves recoverable) include balances related to the life retrocession embedded derivative, under which all investment results associated with the Life Funds Withheld Assets related to the GreyCastle Life Retro Arrangements described in Note 1, "Basis of Preparation and Consolidation," accrue to the benefit of GCLR.

[6] Financial instruments sold, but not yet purchased, represent "short sales" and are included within "Payable for investments purchased" on the balance sheets.

[7] Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities.