CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows - operating activities
Premiums collected	$ 739,503	$ 710,646	$ 723,705
Policyholder benefits paid	(528,501)	(511,017)	(534,359)
Policy acquisition and other operating expenses paid	(283,351)	(277,076)	(267,854)
Income taxes paid	(16,259)	(27,847)	(24,861)
Investment income collected	363,283	344,778	330,034
Interest expense paid	(11,555)	(11,754)	(13,521)
Other	(6,534)	(16,297)	(5,430)
Net cash provided by operating activities	256,586	211,433	207,714
Fixed maturity securities
Purchases	(1,569,220)	(1,566,047)	(1,490,376)
Sales	500,760	429,251	445,100
Maturities, paydowns, calls and redemptions	927,665	799,653	683,335
Equity securities
Purchases	(32,312)	(60,135)	(33,922)
Sales and repayments	53,100	21,210	37,943
Purchase of other invested assets	(117,502)	(83,588)	(38,018)
Net cash provided by (used in) short-term and other investments	8,845	134,296	(19,911)
Net cash used in investing activities	(228,664)	(325,360)	(415,849)
Cash flows - financing activities
Dividends paid to shareholders	(46,114)	(44,310)	(42,523)
Proceeds from issuance of Senior Notes due 2025	0	0	246,937
Redemption of Senior Notes due 2016	0	0	(127,292)
Maturity of Senior Notes due 2015	0	0	(75,000)
Principal repayment on Bank Credit Facility	0	0	(38,000)
FHLB borrowings	50,000	0	0
Acquisition of treasury stock	(1,660)	(21,513)	(21,950)
Proceeds from exercise of stock options	4,190	3,329	1,629
Withholding tax payments on RSUs tendered	(3,245)	(4,015)	(671)
Annuity contracts: variable, fixed and FHLB funding agreements
Deposits	453,146	520,211	623,021
Benefits, withdrawals and net transfers to Separate Account (variable annuity) assets	(411,061)	(349,915)	(354,735)
Transfer of Company 401(k) to a third-party provider	(77,898)	0	0
Life policy accounts
Deposits	4,883	4,018	1,455
Withdrawals and surrenders	(4,458)	(3,965)	(3,985)
Change in bank overdrafts	(4,748)	11,248	3,083
Net cash provided by (used in) financing activities	(36,965)	115,088	211,969
Net increase (decrease) in cash	(9,043)	1,161	3,834
Cash at beginning of period	16,670	15,509	11,675
Cash at end of period	$ 7,627	$ 16,670	$ 15,509