Property and Equipment - Components of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Aircraft	$ 0	$ 19,260
Equipment	21,451	20,930
Furniture and fixtures	7,684	7,639
Leasehold improvements	23,082	22,847
Property, plant and equipment, gross	52,217	70,676
Less accumulated depreciation and amortization	(45,032)	(62,074)
Total property and equipment, net	7,185	$ 8,602
Aircraft [Member]
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition of assets	$ 800

Aircraft, Gross

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

+ References

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-Publisher FASB
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- Definition

Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

+ References

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- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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- Definition

Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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- Definition

Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.

+ References

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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