Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 47,793	$ 37,601
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(25,494)	(24,704)
Property, Plant and Equipment, Net	22,299	12,897
Depreciation Expense	3,552	2,300	$ 1,959
Payments for Flight Equipment	9,900
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	11,823	11,823
Office furnishings, leasehold improvements, computer equipment and computer software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	25,895	25,676
Transportation and construction equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 10,075	$ 102