STOCKHOLDERS' EQUITY (Schedule of Stock by Class) (Details) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Stockholders’ equity:
Common stock, shares authorized (in shares)	200,000,000	200,000,000	[1]
Common stock, shares issued (in shares)	84,375,021	83,724,916	[1]
Undesignated preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Undesignated preferred stock, shares issued (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.000001	$ 0.000001	[1]

[1] As of January 1, 2018, the Company adopted Accounting Standards Update 2014-09, "Revenue from Contracts with Customers (Topic 606)" ("ASC 606"), using the full retrospective method. Accordingly, the Company has recast certain amounts in the prior period presented. See Note 1 below for additional discussion.