Number of square feet of office space in Tysons, Virginia for a new corporate headquarters

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Leases and Other Commitments - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Feb. 28, 2019 ft²	Dec. 31, 2018 USD ($)	Apr. 30, 2018 ft²
Debt Instrument [Line Items]
Operating leases, weighted average remaining lease term	11 years 4 months 24 days
Number of square feet \| ft²		28,805		176,222
Term of lease	150 months
Payment of royalty fees	$ 0.3
Outstanding letters of credit	$ 10.5		$ 10.5
Minimum
Debt Instrument [Line Items]
Operating leases, weighted average remaining lease term	1 year
Maximum
Debt Instrument [Line Items]
Operating leases, weighted average remaining lease term	12 years
Renewal term	5 years