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

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Number of shares authorized for issuance under share-based payment arrangement.

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Stock-Based Compensation - Performance-based Awards (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 31, 2019	Mar. 31, 2019	Jan. 31, 2019
Performance-based awards \| Executive Chairman
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved	425,000			600,000
Compensation expense associated with performance-based awards			$ 3,300
Performance-based awards \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved								200,000
Compensation expense associated with performance-based awards			600
Restricted stock units \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved								100,000
Restricted stock units \| Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved							100,000
Restricted stock units \| Chief Operating Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved							100,000
Restricted stock units \| Chief Financial Officer and Chief Operating Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense associated with performance-based awards			1,200
Restricted stock units \| Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved						188,099
Compensation expense associated with performance-based awards			1,300
Employee and non-employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			28,624	$ 14,198	$ 11,402
Employee and non-employee stock options \| Executive Chairman
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved	200,000
Requisite service period	3 years
Compensation expense associated with performance-based awards			$ 600	$ 400	$ 0
Employee and non-employee stock options \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options vested		37,500