Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Restricted stock	Sep. 30, 2013 Restricted stock	Sep. 30, 2014 Restricted stock	Sep. 30, 2013 Restricted stock	Sep. 30, 2014 SARs	Sep. 30, 2013 SARs	Sep. 30, 2014 SARs	Sep. 30, 2013 SARs	Sep. 30, 2014 Stock options	Sep. 30, 2013 Stock options	Sep. 30, 2014 Stock options	Sep. 30, 2013 Stock options	Sep. 30, 2014 Non employee director deferred compensation	Sep. 30, 2013 Non employee director deferred compensation	Sep. 30, 2014 Non employee director deferred compensation	Sep. 30, 2013 Non employee director deferred compensation	Sep. 30, 2014 Convertible senior note	Sep. 30, 2013 Convertible senior note	Sep. 30, 2014 Convertible senior note	Sep. 30, 2013 Convertible senior note	Nov. 15, 2010 3.25% Convertible Senior Notes due 2016
Reconciliation of Weighted-Average Diluted Shares Outstanding
Weighted average common shares outstanding - basic	35,834,000	33,413,000	35,763,000	31,350,000
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements					259,000	0	287,000	0	56,000	0	45,000	0	1,000	0	1,000	0	6,000	0	5,000	0	672,000	0	730,000	0
Weighted Average Number of Shares Outstanding - Diluted	36,828,000	33,413,000	36,831,000	31,350,000
Anti-dilutive Effect
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	15,000	1,570,000	30,000	1,320,000	4,000	805,000	0	857,000	11,000	83,000	30,000	65,000	0	7,000	0	7,000	0	4,000	0	4,000	0	671,000	0	387,000
Convertible Senior Note Due 2016
3.25% Convertible Note, Shares To Be Received Upon Conversion																									2,700,000
3.25% Convertible Note, Conversion Price																									$ 42.40