Equity Compensation - Options Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding at beginning of period (in shares)	4,533,782		4,664,634		4,455,365
Granted (in shares)	8,977		756,700		761,892
Excercised (in shares)	(33,810)		(30,166)		(9,417)
Canceled (in shares)	(908,817)		(857,386)		(543,206)
Options outstanding at end of period (in shares)	3,600,132		4,533,782		4,664,634
Weighted Average Exercise Price
Options outstanding at beginning of period - Weighted Average Exercise Price (in dollars per share)	$ 23.86		$ 26.21		$ 28.99
Granted - Weighted Average Exercise Price (in dollars per share)	$ 16.71		$ 14.47		$ 13.44
Excercised - Weighted Average Exercise Price (in dollars per share)	$ 14.16		$ 16.94		$ 10.70
Canceled - Weighted Average Exercise Price (in dollars per share)	$ 28.57		$ 28.63		$ 31.52
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share)	$ 22.74		$ 23.86		$ 26.21
Options exercisable at end of period (in shares)	2,954,082		2,985,175		3,074,275
Stock Options
Weighted Average Exercise Price
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share)	$ 22.74
Exercise price range, lower limit (in dollars per shares)	$ 13.37		$ 13.35		$ 13.37
Exercise price range, upper limit (in dollars per shares)	$ 47.80		$ 47.80		$ 47.80
Options available for grant at end of period (in shares)	3,654,426	[1]	4,460,337	[1]	1,248,033	[1]

[1] *Shares available for grant as of December 31, 2014 reduced by net restricted stock / unit and performance share / unit award activity of 369,690 shares and 427,244 shares, respectively.