CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Securities, available-for-sale, at fair value:
Fixed maturities, amortized cost	$ 4,644,561	$ 4,948,543
Shareholders' equity (note 14):
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, shares issued (in shares)	340,047	340,047
Common stock, shares outstanding (in shares)	338,560	337,758
Treasury stock, shares at cost (in shares)	1,487	2,289