Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES
Net income (loss)	$ 577,513	$ (65,594)
Adjustments to reconcile net income (loss) to net cash provided by operating activities	(558,790)	123,266
Net Cash Provided By Operating Activities	18,723	57,672
INVESTING ACTIVITIES
Proceeds from sales of fixed maturities and equity securities	133,453	140,728
Proceeds from maturities, calls and prepayments of fixed maturities	128,449	191,260
Cost of fixed maturities and equity securities purchased	(227,556)	(497,377)
Net change in short-term investments	329,659	129,032
Additions to property and equipment	(24,756)	(23,362)
Proceeds from disposals of fixed assets	13,955	100
Acquisitions, net of cash acquired	(9,400)	(7,809)
Other	(1,684)	(816)
Net Cash Provided (Used) By Investing Activities	342,120	(68,244)
FINANCING ACTIVITIES
Additions to senior long-term debt and other debt	87,356	52,706
Repayment of senior long-term debt and other debt	(36,100)	(102,306)
Repurchases of common stock	(37,649)	(12,289)
Purchase of noncontrolling interests	(9,754)	(6,863)
Distributions to noncontrolling interests	(2,808)	(4,706)
Other	(1,114)	(1,238)
Net Cash Used By Financing Activities	(69)	(74,696)
Effect of foreign currency rate changes on cash, cash equivalents, restricted cash and restricted cash equivalents	7,199	26,074
Increase (decrease) in cash, cash equivalents, restricted cash and restricted cash equivalents	367,973	(59,194)
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of period	2,396,432	2,500,846
CASH, CASH EQUIVALENTS, RESTRICTED CASH AND RESTRICTED CASH EQUIVALENTS AT END OF PERIOD	$ 2,764,405	$ 2,441,652