Employee Benefits - Employee Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan Wage Base	$ 265,000	$ 265,000	$ 260,000
Deferred Compensation Arrangement with Individual, Requisite Service Period	3 years
Defined Contribution Plan, Cost Recognized	$ 1,300,000	$ 1,200,000	$ 1,200,000
Base Percentage [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution percentage to retirement plan	13.20%
Excess Percentage for amounts above Social Security taxable wage base] [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution percentage to retirement plan	5.70%