Annual report pursuant to Section 13 and 15(d)

Business and Summary of Significant Accounting Principles (Surcharges Reported Gross) (Details)

v3.6.0.2
Business and Summary of Significant Accounting Principles (Surcharges Reported Gross) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Accounting Policies [Abstract]      
Surcharges reported gross $ 3,849 $ 5,058 $ 4,252