Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Basic EPS:
Income from continuing operations	$ 3,122	$ 17,007	$ 9,720	$ 63,938
Income from continuing operations, share amounts	42,901,000	42,470,000	42,812,000	42,365,000
Less: Income (Loss) from continuing operations allocated to unvested shares	(68)	(326)	(210)	(1,195)
Income from continuing operations allocated to common shares	3,054	16,681	9,510	62,743
Income from continuing operations allocated to common shares, shares	42,901,000	42,470,000	42,812,000	42,365,000
Income from continuing operations allocated to common shares, per share amount	$ 0.07	$ 0.39	$ 0.22	$ 1.48
Dilutive Securities:
Plus: Income (Loss) from continuing operations allocated to unvested shares	68	326	210	1,195
Less: (Income) loss from continuing operations re-allocated to unvested shares	(68)	(324)	(209)	(1,188)
Stock Options, shares	70,000	208,000	133,000	254,000
Diluted EPS:
Income from Continuing operations allocated to common shares, and assumed share conversions	$ 3,054	$ 16,683	$ 9,511	$ 62,750
Income from Continuing operations allocated to common share, and assumed share conversions, shares	42,971,000	42,678,000	42,945,000	42,619,000
Income from continuing operations allocated to common shares, and assumed share conversions, per share amount	$ 0.07	$ 0.39	$ 0.22	$ 1.47
Earnings Per Share (Textual) [Abstract]
Options to purchase, shares	1,608,466	1,400,000	1,608,466	1,400,000	1,375,281
Options to purchase, exercise price	$ 32.97	$ 32.44	$ 32.97	$ 32.44
Stock options not included in the computation of diluted EPS	1,400,000	800,000	1,100,000	700,000