Earnings Per Share (Details 1) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	60	478	501	919
Stock options [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	60	458	99	627
Restricted stock awards and units [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	0	20	8	30
Performance-based restricted stock units [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	0	0	3	0
Employee stock purchase plan [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	0	0	391	262