Equity Compensation (Options Activity) (Details)	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding at beginning of period (in shares) | shares	2,631,569
Granted (in shares) | shares	0
Excercised (in shares) | shares	(183,349)
Canceled (in shares) | shares	(155,200)
Options outstanding at end of period (in shares) | shares	2,293,020
Weighted Average Exercise Price
Options outstanding at beginning of period - Weighted Average Exercise Price (in dollars per share)	$ 19.44
Granted - Weighted Average Exercise Price (in dollars per share)	0
Excercised - Weighted Average Exercise Price (in dollars per share)	0
Canceled - Weighted Average Exercise Price (in dollars per share)	23.49
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share)	$ 19.58
Options exercisable at end of period (in shares) | shares	1,693,244
Stock Options
Weighted Average Exercise Price
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share)	$ 19.58
Options available for grant at end of period (in shares) | shares	4,014,199	[1]
$ 12.15 – $20.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price range, lower limit (in dollars per share)	$ 12.15
Exercise price range, upper limit (in dollars per share)	20.00
$ 12.15 – $20.00 | Stock Options
Weighted Average Exercise Price
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share)	12.82
$ 30.01 – $33.36
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price range, lower limit (in dollars per share)	30.01
Exercise price range, upper limit (in dollars per share)	33.36
$ 30.01 – $33.36 | Stock Options
Weighted Average Exercise Price
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share)	$ 33.36

[1] *Shares available for grant as of June 30, 2018 reduced by net restricted stock and restricted stock unit award and performance share and performance share unit award activity of 2,684,726 shares and 2,484,402 shares, respectively.