Employee Benefit Plans	12 Months Ended
Dec. 31, 2018
Compensation Related Costs [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANSThe Company maintains a defined contribution retirement plan offered to all of its U.S. employees, as well as plans at certain foreign subsidiaries. The Company makes matching contributions to each plan, which amounted to approximately $4,261, $3,363 and $2,509, respectively for years ended December 31, 2018, 2017 and 2016.The Company has an employee stock purchase plan offered to its U.S. and German employees. The plan allows employees who participate to purchase shares of common stock through payroll deductions at a 15% discount to the lower of the stock price on the first day or the last day of the six-month purchase period. Payroll deductions may not exceed 10% of the employee's compensation and are subject to other limitations. Compensation expense related to the employee stock purchase plan was $925, $967 and $846 for the years ended December 31, 2018, 2017 and 2016, respectively. As of December 31, 2018, there were 387,498 shares available for issuance under the employee stock purchase plan, including 45,184 shares subject to purchase during the current purchase period. Shares subject to purchase were calculated following plan guidelines using the December 31, 2018 closing stock price. Shares available for issuance are subject to approval of the employee stock purchase plan at the 2019 annual meeting of stockholders.

Employee Benefit Plans

12 Months Ended

Dec. 31, 2018

EMPLOYEE BENEFIT PLANSThe Company maintains a defined contribution retirement plan offered to all of its U.S. employees, as well as plans at certain foreign subsidiaries. The Company makes matching contributions to each plan, which amounted to approximately $4,261, $3,363 and $2,509, respectively for years ended December 31, 2018, 2017 and 2016.The Company has an employee stock purchase plan offered to its U.S. and German employees. The plan allows employees who participate to purchase shares of common stock through payroll deductions at a 15% discount to the lower of the stock price on the first day or the last day of the six-month purchase period. Payroll deductions may not exceed 10% of the employee's compensation and are subject to other limitations. Compensation expense related to the employee stock purchase plan was $925, $967 and $846 for the years ended December 31, 2018, 2017 and 2016, respectively. As of December 31, 2018, there were 387,498 shares available for issuance under the employee stock purchase plan, including 45,184 shares subject to purchase during the current purchase period. Shares subject to purchase were calculated following plan guidelines using the December 31, 2018 closing stock price. Shares available for issuance are subject to approval of the employee stock purchase plan at the 2019 annual meeting of stockholders.