Earnings Per Share(Schedule of Weighted Average Number of Shares for calculating diluted earnings per share) (Details) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Weighted Average Number Of Shares Outstanding Basic	30,920	30,745	30,827	30,684
Diluted	31,004	30,997	30,997	30,980
Stock Options [Member]
Common and potential common shares		30		76
Unvested Restricted Stock Units [Member]
Common and potential common shares	84	220	170	218
Unvested Restricted Stock [Member]
Common and potential common shares		2		2