Stockholders' Equity (Reconciliation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stockholders' Equity [Abstract]
Income from continuing operations									$ 47,664	$ 26,738	$ 27,069
Less: Income from continuing operations attributable to noncontrolling interest									(9,808)	(6,344)	(7,312)
Income from continuing operations attributable to common stockholders									37,856	20,394	19,757
Discontinued operations										(420)	20,009
Less: Discontinued operations attributable to noncontrolling interest										107	(5,347)
Discontinued operations attributable to common stockholders										$ (313)	$ 14,662
Basic weighted average number of common shares outstanding									41,860,139	36,682,191	33,040,839
Effect of dilutive stock options									595,708	419,380	100,519
Effect of restricted shares									89,235	68,315	30,758
Diluted weighted average number of common shares outstanding									42,545,082	37,169,886	33,172,116
Basic earnings per share: Income from continuing operations									$ 0.90	$ 0.56	$ 0.60
Basic earnings per share: Discontinued operations										$ (0.01)	$ 0.44
Basic earnings per share: Net income attributable to common stockholders	$ 0.29	$ 0.20	$ 0.21	$ 0.19	$ 0.18	$ 0.15	$ 0.14	$ 0.08	$ 0.90	$ 0.55	$ 1.04
Diluted earnings per share: Income from continuing operations									$ 0.89	$ 0.55	$ 0.60
Diluted earnings per share: Discontinued operations										$ (0.01)	$ 0.44
Diluted earnings per share: Net income attributable to common stockholders	$ 0.29	$ 0.20	$ 0.20	$ 0.19	$ 0.18	$ 0.15	$ 0.14	$ 0.07	$ 0.89	$ 0.54	$ 1.04