Employee Benefit Plans - Summary of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost	$ 110
Period of interest rate swap used to calculate expected life of options	10 years
Number of shares available for stock options (in shares)	19,853
Issuance of common stock (in shares)	101,912	113,373	114,935
Forfeiture Of Shares Of Common Stock Shares (in shares)	5,255	3,296	3,934
Number of Shares
Options Outstanding Beginning Balance (in shares)	9,020	10,220	19,380
Granted (in shares)	5,805	0	0
Exercised (in shares)	(1,800)	(1,200)	(9,160)
Options Outstanding Ending Balance (in shares)	13,025	9,020	10,220	19,380
Weighted- Average Exercise Price
Options Outstanding Weighted Average Exercise Price Beginning Balance (in dollars per share)	$ 33.30	$ 33.44	$ 29.92
Options Outstanding Weighted Average Exercise Price Ending Balance (in dollars per share)	$ 45.92	$ 33.30	$ 33.44	$ 29.92
Weighted-Average Remaining Contractual Term (Years)
Weighted-Average Remaining Contractual Term	5 years 5 months 19 days	3 years 4 months 28 days	4 years 5 months 12 days	3 years 10 days
Aggregate Intrinsic Value (In Thousands)
Aggregate Intrinsic Value	$ 248	$ 250	$ 342	$ 580
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for stock options (in shares)	19,853	38,125
Issuance of common stock (in shares)	23,527
Weighted average number of net shares issued (redeemed)	$ 63.96
Forfeiture Of Shares Of Common Stock Shares (in shares)	5,255
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value	$ 49.91