Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Basic EPS:
Income from continuing operations	$ 3,028	$ 26,682	$ 6,598	$ 46,931
Income from continuing operations, share amounts	42,862,000	42,436,000	42,768,000	42,313,000
Less: Income (Loss) from continuing operations allocated to unvested shares	(68)	(456)	(142)	(807)
Income from continuing operations allocated to common shares	2,960	26,226	6,456	46,124
Income from continuing operations allocated to common shares, shares	42,862,000	42,436,000	42,768,000	42,313,000
Income from continuing operations allocated to common shares, per share amount	$ 0.07	$ 0.62	$ 0.15	$ 1.09
Dilutive Securities:
Plus: Income (Loss) from continuing operations allocated to unvested shares	68	456	142	807
Less: (Income) loss from continuing operations re-allocated to unvested shares	(67)	(454)	(141)	(803)
Stock Options, shares	92,000	229,000	158,000	219,000
Diluted EPS:
Income from Continuing operations allocated to common shares, and assumed share conversions	$ (2,961)	$ (26,228)	$ (6,457)	$ (46,128)
Income from Continuing operations allocated to common share, and assumed share conversions, shares	42,954,000	42,665,000	42,926,000	42,532,000
Income from continuing operations allocated to common shares, and assumed share conversions, per share amount	$ 0.07	$ 0.61	$ 0.15	$ 1.08
Earnings Per Share (Textual) [Abstract]
Options to purchase, shares	1,630,533	1,400,000	1,630,533	1,400,000	1,375,281
Options to purchase, exercise price	$ 32.78	$ 32.39	$ 32.78	$ 32.39
Stock options not included in the computation of diluted EPS	1,300,000	600,000	1,000,000	800,000