Fair Value Measurements (Assets and Liabilities at Fair Value, Recurring Basis) (Details) - Recurring Measurement - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Liabilities:
Earnout consideration liability	$ 3,576	$ 2,500
Level 1
Liabilities:
Earnout consideration liability	0	0
Level 2
Liabilities:
Earnout consideration liability	0	0
Level 3
Liabilities:
Earnout consideration liability	$ 3,576	$ 2,500