Consolidated Statement of Stockholders' Equity (Unaudited) (USD $) In Thousands, unless otherwise specified		Total	Common Stocks [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income, Net of Tax [Member]
Balance, beginning of year at Dec. 31, 2013		$ 782,833	$ 25	$ 211,574	$ 484,084	$ 87,150
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased			0	(11,249)
Compensation expense and related tax benefit for stock-based award grants				1,351
Shares issued for stock-based awards			0	1,782
Net income		24,341			24,341
Dividends on common stock ($0.58 per share)					(14,672)
Change in net unrealized investment appreciation	[1]					22,551
Change in liability for underfunded employee benefit plans	[2]					1,497
All other changes in stockholders’ equity accounts		1,260
Balance, end of year at Sep. 30, 2014		$ 808,434	$ 25	$ 203,458	$ 493,753	$ 111,198

[1] The change in net unrealized appreciation is net of reclassification adjustments and income taxes.

[2] The change in liability for underfunded employee benefit plans is net of reclassification adjustments and income taxes.