Stock-Based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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]
Stock-based compensation costs	$ 4,109	$ 6,196	$ 6,661
Tax benefit from compensation expense	$ 888	$ 1,475	$ 2,219
Class A Non-Voting
Summary of Option Activity, Shares
Outstanding beginning balance (in shares)	1,294	887	489
Granted (in shares)	591	582	654
Exercised (in shares)	(111)	(21)	(70)
Forfeited or expired (in shares)	(80)	(154)	(186)
Outstanding ending balance (in shares)	1,694	1,294	887	489
Exercisable at end of period (in shares)	702
Summary of Option Activity, Weighted-Average Exercise Price
Outstanding beginning balance, weighted-average exercise price (in usd per share)	$ 8.60	$ 8.53	$ 7.19
Granted, weighted-average exercise price (in usd per share)	9.70	8.60	9.44
Exercised, weighted-average exercise price (in usd per share)	5.91	4.88	5.77
Forfeited or expired, weighted-average exercise price (in usd per share)	9.24	8.74	9.24
Outstanding ending balance, weighted-average exercise price (in usd per share)	9.13	$ 8.60	$ 8.53	$ 7.19
Exercisable at end of period, weighted-average exercise price (in usd per share)	$ 8.91
Summary of Option Activity, Weighted-Average Remaining Contractual Term
Outstanding, weighted-average remaining contractual term	7 years 10 months 10 days	8 years 1 month 5 days	8 years 5 months 2 days	7 years 2 days
Exercisable at end of period, weighted-average remaining contractual term	6 years 10 months 23 days
Outstanding, aggregate intrinsic value	$ 3,969	$ 667	$ 527
Exercisable at end of period, aggregate intrinsic value	$ 1,795
Weighted average grant date fair value, options granted during period (in usd per share)	$ 2.57	$ 2.78	$ 2.73
Options, exercised in period, intrinsic value	$ 446	$ 80	$ 234
Options, vested in period, fair value	$ 1,000	$ 36	33
Stock options
Summary of Option Activity, Weighted-Average Remaining Contractual Term
Expected dividend yield	3.80%	3.50%
Expected volatility	36.73%	42.67%
Risk-free interest rate	2.56%	2.75%
Expected term of options	7 years	7 years
Stock options | Class A Non-Voting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based award vesting period	3 years
Stock option vesting per year (percent)	33.00%
Stock options expiration period	10 years
Share-based compensation expense	$ 1,397	$ 1,253	$ 1,233
Summary of Option Activity, Weighted-Average Remaining Contractual Term
Unearned compensation cost	$ 889