Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income	$ 38,339,000	$ 63,830,000	$ 43,566,000
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred policy acquisition costs	(91,449,000)	(93,188,000)	(123,577,000)
Amortization of policy acquisition costs	83,893,000	111,103,000	116,001,000
Net realized investment losses	2,919,000	5,479,000	1,989,000
Impairment of intangible assets	0	200,000	0
Distributions from equity method investments	2,834,000	7,499,000	7,333,000
Income from equity method investments	(4,598,000)	(3,540,000)	(13,209,000)
Trading securities purchases, sales, and maturities, net	0	3,804,000	1,250,000
Deferred U.S. federal income tax benefit	(4,925,000)	(5,859,000)	(364,000)
Provision for depreciation and amortization	4,063,000	4,215,000	2,123,000
Share based compensation expense	7,178,000	6,228,000	7,688,000
Excess tax benefits from equity incentive plan transactions	(1,099,000)	(2,699,000)	(2,115,000)
Change in operating assets and liabilities:
Reserve for losses and loss adjustment expenses	384,047,000	369,110,000	348,484,000
Unearned premiums	137,904,000	(31,641,000)	27,551,000
Premiums receivable and agents’ balances	(61,563,000)	44,537,000	(87,121,000)
Reinsurance balances	(235,632,000)	(187,024,000)	(113,665,000)
Funds held	1,199,164,000	0	0
Payable to insurance companies	263,000	(2,029,000)	445,000
Other	27,684,000	3,000	(8,563,000)
Net cash provided by operating activities	1,489,022,000	290,028,000	207,816,000
Securities available-for-sale:
Purchases – fixed maturity securities	(450,793,000)	(418,011,000)	(270,014,000)
Sales – fixed maturity securities	121,245,000	95,793,000	77,781,000
Maturities and calls – fixed maturity securities	128,809,000	129,139,000	121,890,000
Purchases – equity securities	(4,975,000)	(7,507,000)	(5,540,000)
Sales – equity securities	8,656,000	5,578,000	3,522,000
Bank loan participations:
Purchases	(102,794,000)	(203,328,000)	(240,799,000)
Sales	48,415,000	123,114,000	138,214,000
Maturities	45,277,000	58,742,000	69,740,000
Other invested assets:
Purchases	0	(6,993,000)	(8,913,000)
Return of capital	1,877,000	921,000	0
Redemptions	10,998,000	0	0
Securities receivable or payable, net	5,404,000	2,268,000	(2,525,000)
Short-term investments, net	(74,959,000)	(45,162,000)	14,040,000
Other	(519,000)	(1,326,000)	(2,137,000)
Net cash used in investing activities	(263,359,000)	(266,772,000)	(104,741,000)
Financing activities
Senior debt issuances	60,000,000	20,000,000	10,000,000
Senior debt repayments	(20,000,000)	0	0
Dividends paid	(36,720,000)	(36,123,000)	(50,832,000)
Issuances of common shares under equity incentive plans	8,286,000	5,172,000	1,708,000
Common share repurchases	(2,899,000)	(2,239,000)	(9,448,000)
Other financing activities	(711,000)	(1,104,000)	(792,000)
Net cash provided by (used in) financing activities	7,956,000	(14,294,000)	(49,364,000)
Change in cash, cash equivalents, and restricted cash equivalents	1,233,619,000	8,962,000	53,711,000
Cash and cash equivalents at beginning of year	172,457,000	163,495,000	109,784,000
Cash, cash equivalents ($206,912), and restricted cash equivalents ($1,199,164) at end of year	1,406,076,000	172,457,000	163,495,000
Supplemental information
U.S. federal income taxes paid, net	18,719,000	8,174,000	9,848,000
Interest paid	$ 12,354,000	$ 11,269,000	$ 8,909,000