Consolidated Statements of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity at beginning of year	$ 346,712	$ 319,061	$ 368,735
Net income (loss)	36,588	31,919	(28,175)
Other comprehensive income (loss)	13,047	9,092	(7,532)
Cash dividends paid to shareholders	(14,943)	(14,886)	(14,846)
Issuance of common stock	320	1,526	879
Shareholders' equity at end of year:	$ 381,724	$ 346,712	$ 319,061