Earnings per Share (Details) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Earnings per Share
Net income / (loss) from continuing operations, net of noncontrolling interests in subsidiaries	$ 3,014	$ (70,074)	$ 4,135	$ (58,565)
Income / (loss) on discontinued operations	0	(7,922)	0	(42,795)
Net income / (loss)	$ 3,014	$ (77,996)	$ 4,135	$ (101,360)	$ (104,667)
Weighted average shares of common stock outstanding (used to calculate basic EPS)	72,479,000	70,135,000	71,846,000	69,667,000
Net effect of dilutive employee stock options based on the treasury stock method	45,000	286,000	72,000	345,000
Weighted average shares of common stock outstanding (used to calculate diluted EPS)	72,524,000	70,421,000	71,918,000	70,013,000
Net income / (loss) per common share - basic:
Continuing operations	$ 0.04	$ (1.00)	$ 0.06	$ (0.84)
Discontinued operations	$ 0.00	$ (0.11)	$ 0.00	$ (0.61)
Net income / (loss) per common share - basic	$ 0.04	$ (1.11)	$ 0.06	$ (1.45)
Net income / (loss) per common share - diluted:
Continuing operations	$ 0.04	$ (1.00)	$ 0.06	$ (0.84)
Discontinued operations	$ 0.00	$ (0.11)	$ 0.00	$ (0.61)
Net income / (loss) per common share - diluted	$ 0.04	$ (1.11)	$ 0.06	$ (1.45)
Adjustment to fully diluted shares related to the convertible senior notes	0