Equity Compensation Plans and Equity (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restricted Stock and Restricted Stock Units
Restricted stock awards including restricted stock units, Shares
Nonvested at the beginning of the period (in shares)	618,000
Granted (in shares)	324,000
Vested (in shares)	(167,000)
Forfeited (including cancelled awards) (in shares)	(82,000)
Nonvested at the end of the period (in shares)	693,000
Weighted-Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 33.61
Granted (in dollars per share)	$ 32.62
Vested (in dollars per share)	$ 20.60
Forfeited (including cancelled awards) (in dollars per share)	$ 34.98
Nonvested at the end of the period (in dollars per share)	$ 36.11
Stock options
Stock option awards, Shares
Outstanding at the beginning of the period (in shares)	2,106,000
Granted (in shares)	704,000
Exercised (in shares)	(351,000)
Forfeited (including cancelled options) (in shares)	(137,000)
Outstanding at the end of the period (in shares)	2,322,000	2,106,000
Options exercisable at the end of the period (in shares)	1,282,000
Weighted Average Exercise price
Outstanding at the beginning of the period (in dollars per share)	$ 25.58
Granted (in dollars per share)	$ 32.55
Exercised (in dollars per share)	$ 15.39
Forfeited (including cancelled options) (in dollars per share)	$ 35.88
Outstanding at the end of the period (in dollars per share)	$ 28.63	$ 25.58
Options exercisable at the end of the period (in dollars per share)	$ 22.63
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	$ 13,149,000
Options exercisable at the end of the period (in dollars)	12,948,000
Weighted Average Remaining Contractual Life
Outstanding at the end of the period	6 years 4 months 24 days
Options exercisable at the end of the period	4 years 6 months
Other disclosures
Weighted-average grant date fair value (in dollars per share)	$ 15.56	$ 21.90	$ 18.41
Total intrinsic value of stock options exercised	$ 6,800,000	$ 22,800,000	$ 53,100,000