XML 91 R78.htm IDEA: XBRL DOCUMENT v3.6.0.2
Employee Benefit Plans - Summary of Estimated Contributions (Detail)
12 Months Ended
Dec. 31, 2016
USD ($)
Supplemental Employee Retirement Plan [Member]  
Defined Contribution Plan Disclosure [Line Items]  
Estimated contributions for 2017 $ 422,656
Postretirement Benefits [Member]  
Defined Contribution Plan Disclosure [Line Items]  
Estimated contributions for 2017 $ 113,268