Stockholder's Equity (Details) (USD $) In Thousands, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Equity attributable to noncontrolling interest
Non-controlling interest, January 1			$ 37,631	$ 3,448
Non-controlling interest in subsidiaries	71	201	280	108
Foreign currency translation adjustment			244	241
Capital contribution by noncontrolling interest			115	31,000
Non-controlling interest, June 30	$ 38,270	$ 34,797	$ 38,270	$ 34,797
Stockholder's Equity (Textual) [Abstract]
Certain Class B stockholders converted into Class A	0	34,900	13,640	1,049,005