Segment information (Tables)

3 Months Ended

Mar. 31, 2020

Segment Reporting [Abstract]

Summary segment information

The following table provides summary information regarding premiums written and earned by line of business and net premiums written by underwriting location:

	Three Months Ended March 31,
	2020		2019
	($ in thousands)
Gross premiums written:
Casualty reinsurance	$	83,818	$	75,601
Other specialty reinsurance	36,880		24,298
Property catastrophe reinsurance	9,832		5,992
Insurance programs and coinsurance	104,372		80,798
Total	$	234,902	$	186,689
Net premiums written:
Casualty reinsurance	$	83,667	$	75,065
Other specialty reinsurance	35,484		23,182
Property catastrophe reinsurance	9,832		5,982
Insurance programs and coinsurance	57,717		41,158
Total	$	186,700	$	145,387
Net premiums earned:
Casualty reinsurance	$	52,765	$	63,313
Other specialty reinsurance	35,364		44,561
Property catastrophe reinsurance	4,884		2,971
Insurance programs and coinsurance	47,026		35,249
Total	$	140,039	$	146,094
Net premiums written by underwriting location:
United States	$	36,303	$	18,402
Europe	21,203		23,258
Bermuda	129,194		103,727
Total	$	186,700	$	145,387