Equity-based Incentive Plans (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2011 year
Range of Exercise Price $0 to $10
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of the range (in dollars per share)	$ 0
Exercise price per share, high end of the range (in dollars per share)	$ 10
Outstanding Options (in shares)	1,530,294
Weighted Average Remaining Contractual Life (Years)	1.9
Weighted Average Exercise Price Outstanding Options (per share)	$ 5.23
Exercisable Options (in shares)	1,530,294
Weighted Average Exercise Price Exercisable Options (in dollars per share)	$ 5.23
Range of Exercise Price $10 to $15
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of the range (in dollars per share)	$ 10
Exercise price per share, high end of the range (in dollars per share)	$ 15
Outstanding Options (in shares)	3,094,843
Weighted Average Remaining Contractual Life (Years)	4.0
Weighted Average Exercise Price Outstanding Options (per share)	$ 13.13
Exercisable Options (in shares)	1,498,555
Weighted Average Exercise Price Exercisable Options (in dollars per share)	$ 13.76
Range of Exercise Price $15 to $20
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of the range (in dollars per share)	$ 15
Exercise price per share, high end of the range (in dollars per share)	$ 20
Outstanding Options (in shares)	2,781,396
Weighted Average Remaining Contractual Life (Years)	3.9
Weighted Average Exercise Price Outstanding Options (per share)	$ 16.39
Exercisable Options (in shares)	2,781,396
Weighted Average Exercise Price Exercisable Options (in dollars per share)	$ 16.39
Range of Exercise Price $20 to $30
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of the range (in dollars per share)	$ 20
Exercise price per share, high end of the range (in dollars per share)	$ 30
Outstanding Options (in shares)	741,037
Weighted Average Remaining Contractual Life (Years)	0.7
Weighted Average Exercise Price Outstanding Options (per share)	$ 24.50
Exercisable Options (in shares)	741,037
Weighted Average Exercise Price Exercisable Options (in dollars per share)	$ 24.50
Range of Exercise Price $30 to $40
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of the range (in dollars per share)	$ 30
Exercise price per share, high end of the range (in dollars per share)	$ 40
Outstanding Options (in shares)	454,712
Weighted Average Remaining Contractual Life (Years)	1.4
Weighted Average Exercise Price Outstanding Options (per share)	$ 37.84
Exercisable Options (in shares)	454,712
Weighted Average Exercise Price Exercisable Options (in dollars per share)	$ 37.84