Taxes - Changes in the Reserve for Income Taxes, Excluding Interest and Penalties (Details) - USD ($) $ in Thousands |
12 Months Ended | |
---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Income Tax Disclosure [Abstract] | ||
Balance of reserve for income taxes | $ 5,719 | $ 5,296 |
Gross amounts of increases in unrecognized tax benefits as a result of tax positions taken in prior periods | 11 | |
Unrecognized Tax Benefits, Period Increase (Decrease) | (56) | |
Gross amounts of increases in unrecognized tax benefits as a result of tax positions taken in the current period | 1,993 | 1,235 |
Gross amounts of decreases in unrecognized tax benefits relating to settlements with taxing authorities | (116) | 0 |
Gross amounts of decreases in unrecognized tax benefits as a result of the expiration of the applicable statutes of limitations | (791) | (823) |
Balance of reserve for income taxes | $ 6,749 | $ 5,719 |