XML 31 R18.htm IDEA: XBRL DOCUMENT

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan The Company maintains a 401(k) savings plan covering substantially all of its employees. Eligible employees may contribute up to 80% of their annual salary through payroll deductions, but not more than the statutory limits set by the Internal Revenue Service. The Company matches employee contributions at the discretion of the Board. During 2018, 2017 and 2016, the Company’s matching contributions totaled $27 million, $20 million and $16 million, respectively.