Other Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
401(k) matching contributions	$ 12,100	$ 11,300	$ 9,800
Pension liability	$ 1,500	$ 1,300