Defined Contribution, Bonus, and Profit Sharing Plans - Schedule of Bonus and Profit Sharing Plans Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution, Bonus, and Profit Sharing [Abstract]
Bonus and profit sharing plans and award expense	$ 15,466	$ 40,005	$ 43,377