Employee Benefit Plan	12 Months Ended
Dec. 31, 2017
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit PlanThe Company has a tax-qualified defined contribution plan (the Plan). The Plan provides retirement benefits, including provisions for early retirement and disability benefits, as well as a tax-deferred savings feature. After satisfying certain requirements, participants are vested in employer contributions at the time the contributions are made. All Company contributions are discretionary and are made from available profits. The Company contributed $10,929, $9,665 and $9,162 to the Plan in 2017, 2016 and 2015, respectively.

Employee Benefit Plan

12 Months Ended

Dec. 31, 2017

Employee Benefit PlanThe Company has a tax-qualified defined contribution plan (the Plan). The Plan provides retirement benefits, including provisions for early retirement and disability benefits, as well as a tax-deferred savings feature. After satisfying certain requirements, participants are vested in employer contributions at the time the contributions are made. All Company contributions are discretionary and are made from available profits. The Company contributed $10,929, $9,665 and $9,162 to the Plan in 2017, 2016 and 2015, respectively.