Net Loss Per Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive securities excluded from computation of earnings per share, amount	7,752	5,185
Convertible Notes [Member]
Antidilutive securities excluded from computation of earnings per share, amount	4,435	2,316
Stock Options [Member]
Antidilutive securities excluded from computation of earnings per share, amount	2,446	2,224
Restricted Stock Units (RSUs) [Member]
Antidilutive securities excluded from computation of earnings per share, amount	871	645