Significant Accounting Policies Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Accumulated Deficit
Item Effected [Line Items]
ASU 2016-09 adoption adjustment	$ (699)
Parent [Member]
Item Effected [Line Items]
ASU 2016-09 adoption adjustment	440
Additional Paid-in- Capital
Item Effected [Line Items]
ASU 2016-09 adoption adjustment	1,139
Other Noncurrent Assets [Member] | Parent [Member]
Item Effected [Line Items]
ASU 2016-09 adoption adjustment	$ 440