CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net revenues:
Rental	$ 39,837	$ 120,365	$ 181,570
Services	181,264	131,996	87,460
Sales	32,989	49,012	35,804
Net revenues:	254,090	301,373	304,834
Cost of revenues:
Rental	28,637	98,162	145,760
Services	54,767	43,794	31,158
Sales	36,197	47,893	34,067
Cost of revenues:	119,601	189,849	210,985
Gross profit	134,489	111,524	93,849
Operating expenses:
Technology and development	66,331	59,391	49,386
Sales and marketing	53,949	64,082	72,315
General and administrative	55,372	45,209	41,837
Restructuring (credits) charges	(423)	4,868	0
Gain on liquidation of textbooks	(670)	(4,326)	(4,555)
Total operating expenses	174,559	169,224	158,983
Loss from operations	(40,070)	(57,700)	(65,134)
Interest expense, net and other (expense) income, net:
Interest expense, net	(171)	(247)	(317)
Other (expense) income, net	(297)	216	879
Total interest expense, net and other (expense) income, net	(468)	(31)	562
Loss before provision for income taxes	(40,538)	(57,731)	(64,572)
Provision for income taxes	1,707	1,479	186
Net loss	$ (42,245)	$ (59,210)	$ (64,758)
Net loss per share, basic and diluted (in dollars per share)	$ (0.47)	$ (0.68)	$ (0.78)
Weighted average shares used to compute net loss per share, basic and diluted (in shares)	90,534	86,818	83,205