Reinsurance (Tables)

12 Months Ended

Dec. 31, 2017

Reinsurance [Abstract]

Summary of the Effects of Reinsurance

	2017		2016
WRITTEN
Direct	$	53,670,397	$	51,031,003
Reinsurance assumed		269,184		307,597
Reinsurance ceded		(7,952,661)		(8,111,446)
Net	$	45,986,920	$	43,227,154
EARNED
Direct	$	51,862,625	$	50,190,888
Reinsurance assumed		299,086		318,476
Reinsurance ceded		(7,948,440)		(7,898,000)
Net	$	44,213,271	$	42,611,365
LOSSES AND SETTLEMENT EXPENSES INCURRED
Direct	$	37,543,652	$	33,388,283
Reinsurance assumed		150,051		149,719
Reinsurance ceded		(8,683,870)		(9,193,451)
Net	$	29,009,833	$	24,344,551

Summary of Net Reinsurance Balances Recoverable

			Net Reinsurer		Ceded
	A.M. Best	S & P	Exposure as of	Percent of	Premiums	Percent of
(In thousands)	Rating	Rating	December 31, 2017	Total	Written	Total
Everest Reinsurance Company	A+	A+	2,700	24.1%	856	10.8%
Aspen Insurance UK Ltd	A	A	2,111	18.9%	1,308	16.4%
Hannover Ruckversicherungs	A+	AA-	1,885	16.9%	1,114	14.0%
Partner Reinsurance Company	A	A+	1,268	11.3%	461	5.8%
Arch Reinsurance Company	A+	A+	1,241	11.1%	86	1.1%
Platinum Underwriters	A	A-	1,169	10.5%	765	9.6%
Swiss Reinsurance	A+	AA-	1,120	10.0%	385	4.8%
Toa Reinsurance Company	A	A+	1,017	9.1%	2	0.0%
Allied World Reinsurance	A	A	680	6.1%	883	11.1%
Endurance Reinsurance	A	A	521	4.7%	547	6.9%
All other reinsurers including anticipated subrogation			(2,529)	-22.6%	1,546	19.4%
			11,183	100.0%	7,953	100.0%