9. Reinsurance

(a) Reinsurance Recoverable on Paid and Unpaid Losses

The Company uses retrocessional agreements to reduce its exposure to risk of loss on reinsurance assumed. These agreements provide for recovery from retrocessionaires of a portion of losses and loss expenses. The Company remains liable to its cedants to the extent that the retrocessionaires do not meet their obligations under these agreements, and therefore the Company evaluates the financial condition of its reinsurers and monitors concentration of credit risk on an ongoing basis. The Company actively manages its reinsurance exposures by generally selecting retrocessionaires having a credit rating of A- or higher. In certain cases where an otherwise suitable retrocessionaire has a credit rating lower than A-, the Company generally requires the posting of collateral, including escrow funds and letters of credit, as a condition to its entering into a retrocession agreement. The Company regularly reviews its reinsurance recoverable balances to estimate an allowance for uncollectible amounts based on quantitative and qualitative factors. There was no allowance for uncollectible reinsurance recoverable at December 31, 2017 deemed necessary based on the quantitative and qualitative analysis as collectability was determined to be reasonably assured and given that any recoverables related to reinsurers with ratings below A- or unrated are collateralized. The allowance for uncollectible reinsurance recoverable was $12 million at December 31, 2016.

(b) Ceded Reinsurance

Net premiums written, net premiums earned and losses and loss expenses are reported net of reinsurance in the Company’s Consolidated Statements of Operations. Assumed, ceded and net amounts for the years ended December 31, 2017, 2016 and 2015 were as follows (in thousands of U.S. dollars):



	Premiums Written		Premiums Earned		Losses and Loss Expenses
2017
Assumed	$	5,587,894	$	5,471,546	$	4,458,290
Ceded	467,968		446,565		617,308
Net	$	5,119,926	$	5,024,981	$	3,840,982

2016
Assumed	$	5,356,942	$	5,343,831	$	3,412,648
Ceded	403,472		374,235		164,557
Net	$	4,953,470	$	4,969,596	$	3,248,091

2015
Assumed	$	5,547,525	$	5,570,321	$	3,215,665
Ceded	317,977		301,143		58,245
Net	$	5,229,548	$	5,269,178	$	3,157,420