SCHEDULE II-CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY) - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Adjustments to reconcile net losses to net cash provided by (used in) operating activities:
Net realized (gains) losses	$ (14,207)	$ (7,534)	$ (4,802)	$ (13,286)	$ (9,542)	$ (5,708)	$ (10,431)	$ (6,501)	$ (39,829)	$ (32,182)	$ (22,036)
Depreciation									5,406	4,557	3,765
Other items, net									15,006	10,818	13,104
Change in:
Stock option excess tax benefit									(11,413)	(1,766)	(6,310)
Changes in investment in unconsolidated investees:
Undistributed earnings									(10,914)	(12,338)	(10,915)
Dividends received										6,600	13,200
Net cash provided by operating activities									152,586	123,085	134,966
Purchase of:
Fixed income, available-for-sale									(665,422)	(470,210)	(545,899)
Property and equipment									(10,035)	(7,121)	(17,531)
Sale of:
Fixed income, available-for-sale									436,680	342,308	173,694
Short-term investments, net									6,637	11,401	7,230
Property and equipment									76	276	1,492
Call or maturity of:
Fixed income, available-for-sale									156,980	101,517	224,620
Net cash provided by (used in) investing activities									(60,597)	22,771	(101,932)
Cash flows from financing activities
Excess tax benefit from exercise of stock options									11,413	1,766	6,310
Stock plan share issuance									(3,364)	3,386	318
Proceeds from issuance of senior notes											149,571
Payment on senior notes											(99,504)
Debt issue costs paid											(1,437)
Net cash used in financing activities									(111,528)	(154,705)	(37,879)
Net (decrease) increase in cash									(19,539)	(8,849)	(4,845)
Cash at the beginning of year				30,620				39,469	30,620	39,469	44,314
Cash at end of year	11,081				30,620				11,081	30,620	39,469
PARENT COMPANY
Cash flows from operating activities
Earnings (loss) before equity in net earnings of subsidiaries									(922)	3,242	5,822
Adjustments to reconcile net losses to net cash provided by (used in) operating activities:
Net realized (gains) losses									(139)	(271)	850
Depreciation									237	238	90
Other items, net									530	737	(1,789)
Change in:
Affiliate balances receivable/payable									4,211	(1,453)	1,349
Federal income taxes									14,227	3,982	5,288
Stock option excess tax benefit									(11,413)	(1,766)	(6,310)
Changes in investment in unconsolidated investees:
Undistributed earnings									(9,893)	(12,009)	(10,915)
Dividends received										6,600	13,200
Net cash provided by operating activities									(3,162)	(700)	7,585
Purchase of:
Fixed income, available-for-sale									(16,031)	(30,850)	(99,982)
Short-term investments, net											(12,963)
Property and equipment											(2,827)
Sale of:
Fixed income, available-for-sale									7,048
Short-term investments, net									91	13,217
Call or maturity of:
Fixed income, available-for-sale									9,507	3,235	101,000
Cash dividends received-subsidiaries									125,000	185,000	40,000
Net cash provided by (used in) investing activities									125,615	170,602	25,228
Cash flows from financing activities
Excess tax benefit from exercise of stock options									11,413	1,766	6,310
Stock plan share issuance									(3,364)	3,386	318
Proceeds from issuance of senior notes											149,571
Payment on senior notes											(99,504)
Debt issue costs paid											(1,437)
Cash dividends paid									(130,698)	(174,861)	(101,913)
Net cash used in financing activities									(122,649)	(169,709)	(46,655)
Net (decrease) increase in cash									(196)	193	(13,842)
Cash at the beginning of year				$ 374				$ 181	374	181	14,023
Cash at end of year	$ 178				$ 374				178	374	181
Interest paid on outstanding debt									$ 7,300	$ 7,000	$ 8,400