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Employee Benefit Plans - Additional Information (Details) - USD ($)		12 Months Ended			31 Months Ended
	Jan. 01, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Jun. 14, 2017
Employee Benefit Plans
Profit sharing contributions		$ 0	$ 0	$ 0
Employer contribution to Plan		$ 2,500,000	$ 2,100,000	1,500,000
Common Stock
Employee Benefit Plans
Stock issued under employee stock purchase plans		26,828	8,882		35,710
Employee Stock Purchase Plan
Employee Benefit Plans
Common stock reserved for sale		164,290			164,290	200,000
Compensation expense		$ 190,000	$ 66,000	$ 0
3% contributed by employees
Employee Benefit Plans
Employer matching contribution	100.00%
Contribution by employees	3.00%
2% contributed by employees
Employee Benefit Plans
Employer matching contribution	50.00%
Contribution by employees	2.00%

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

Amount of cost for defined contribution plan.

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Amount of discretionary contributions made by an employer to a defined contribution plan.

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