Equity Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		95 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013
Number of Stock Options
Equity based compensation expense, net of forfeitures recognized	$ 6,500	$ 4,700	$ 18,795	$ 16,650	$ 79,501
Restricted Stock
Number of shares relating to award
Granted (in shares)			605,940
Restricted Stock | Non-employee directors
Number of shares relating to award
Granted (in shares)			34,833
Retainer awards | Non-employee directors | Common Stock
Number of shares relating to award
Granted (in shares)			11,056
Stock options
Number of Stock Options
Granted (in shares)			959,023