Employee Benefit Plans - Summary of Assumptions Used to Determine Benefit Obligations For Defined Plans (Details)	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plans [Member]
Assumptions used to determine defined benefit plan obligations [Abstract]
Discount rate	3.75%	3.46%
Rate of compensation increases	4.32%	4.54%
SERP [Member]
Assumptions used to determine defined benefit plan obligations [Abstract]
Discount rate	3.39%	3.14%
Rate of compensation increases	4.26%	4.42%