Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details)

v3.8.0.1
Fair Value Measurements (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Fair Value on Non-Recurring Basis      
Fair value assets level 1 to 2 transfers $ 0 $ 0 $ 0
Fair value assets level 2 to 1 transfers 0 0 0
Fair value liabilities level 1 to 2 transfers 0 0 0
Fair value liabilities level 2 to 1 transfers $ 0 $ 0 $ 0