Fair Value Measurements (Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Restricted cash balance	$ 216	$ 1,451
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	2,811	2,871
Liabilities	0	2
Recurring [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	2
Recurring [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	2,811	2,806
Recurring [Member] | Derivative Financial Instruments, Assets [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	65
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	2,811	2,806
Liabilities	0	0
Recurring [Member] | Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Recurring [Member] | Level 1 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	2,811	2,806
Recurring [Member] | Level 1 [Member] | Derivative Financial Instruments, Assets [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	65
Liabilities	0	2
Recurring [Member] | Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	2
Recurring [Member] | Level 2 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Recurring [Member] | Level 2 [Member] | Derivative Financial Instruments, Assets [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	65
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Recurring [Member] | Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Recurring [Member] | Level 3 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Recurring [Member] | Level 3 [Member] | Derivative Financial Instruments, Assets [Member] | Foreign Currency Derivatives Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 0	$ 0