Accounts and Other Receivables, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	$ 55,041	$ 197,962
Allowance for doubtful accounts	(254)	(21)
Accounts and other receivables, net	54,787	197,941
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	28,850	156,705
Unbilled Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	6,422	17,264
Advance Billings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	596	1,915
Short-Term Tnvestment In Sales-Type Lease [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	8,904	8,683
Other Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	$ 10,269	$ 13,395
Non-US Government Customers [Member] | Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk, percent	16.00%	24.00%
Government Contracts Concentration Risk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, net	$ 13,900	$ 104,600
Government Contracts Concentration Risk [Member] | Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, net	$ 1,600	$ 1,400