Employee Benefit Plans - Profit Sharing Plan (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan Disclosure [Line Items]
Profit sharing expense		$ 42,879	$ 43,104	$ 41,886
Profit Sharing Expense
Defined Contribution Plan Disclosure [Line Items]
Profit sharing expense	[1]	8,226	7,803	7,346
Company dividends received by the Profit Sharing Plan		$ 414	$ 457	$ 441
Company shares held by the Profit Sharing Plan at the end of the year:
Number of shares		812,886	1,047,213	1,079,975
Fair value		$ 18,745	$ 20,745	$ 25,930

[1] Included in retirement and other employee benefits in the Consolidated Statements of Income.