STOCKHOLDERS' EQUITY AND COMPENSATION ARRANGEMENTS Stock Plan (Tables)

9 Months Ended

Sep. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

are administered by the Compensation Committee of the Board (the "Compensation Committee"). As of September 30, 2018, 54,556,190 shares of common stock were available for future issuance under the Plans.

The stock-based compensation expense related to stock awards issued under the Plans and acquisition-related awards are presented within the following line items of the condensed consolidated statements of operations for the three and nine months ended September 30, 2018 and 2017 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Cost of revenue	$	419	$	582	$	1,103	$	2,039
Marketing	1,854		1,797		5,411		5,829
Selling, general and administrative	12,753		15,856		44,056		51,409
Restructuring charges	—		849		—		849
Other income (expense)	—		93		100		192
Total stock-based compensation expense	$	15,026	$	19,177	$	50,670	$	60,318

We also capitalized $2.0 million and $1.4 million of stock-based compensation for the three months ended September 30, 2018 and 2017, respectively, and $5.7 million and $4.7 million for the nine months ended September 30, 2018 and 2017, respectively, in connection with internally-developed software. As of September 30, 2018, $112.2 million of unrecognized compensation costs related to unvested employee stock awards are expected to be recognized over a remaining weighted-average period of 1.36 years.