XML 75 R51.htm IDEA: XBRL DOCUMENT v3.7.0.1
Commitments (Details Textual) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Commitments And Contingencies Disclosure [Line Items]    
Purchase Commitment, Remaining Minimum Amount Committed $ 140,516 $ 135,054