Earnings Per Share Antidilutive Securities (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,311	3,416	949
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 84.96
Stock Incentive Plans [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	943	48	1
Convertible note hedge and capped call transactions [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	948	[1]
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,368	3,368	0

[1] The convertible note hedge and capped call transactions offset any dilution upon actual conversion of the Convertible Notes up to a common stock price of $84.96. See Note 7 for further information.