Employee Benefit Plans - Restricted Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Units
Granted (in shares)	83,683
Restricted Stock Units (RSUs)
Units
Non vested balance at beginning of period (in shares)	329,205	368,492	527,486
Granted (in shares)	45,993	42,136	47,514
Forfeited (in shares)	(22,934)	(1,080)	(3,508)
Vested (in shares)	(235,409)	(80,343)	(203,000)
Non vested balance at end of period (in shares)	116,855	329,205	368,492
Weighted Average  Grant-Date Fair Value
Non vested balance at beginning of period (in dollars per share)	$ 25.42	$ 17.20	$ 10.17
Granted (in dollars per share)	77.78	78.37	42.93
Forfeited (in dollars per share)	57.27	28.30	25.74
Vested (in dollars per share)	12.54	15.42	4.82
Non vested balance at end of period (in dollars per share)	$ 65.73	$ 25.42	$ 17.20