Stock Based Compensation - Stock Options Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Option Shares
Outstanding at beginning of period (in shares)			13,200
Business combinations options acquired (in shares)			40,753
Granted (in shares)			0
Exercised (in shares)	(1,826)	(3,300)	(32,356)	(35,310)
Forfeited (in shares)			(2,075)
Expired (in shares)			(830)
Outstanding at end of period (in shares)	18,692		18,692
Exercisable at end of period (in shares)	14,276		14,276
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per share)			$ 21.97
Business combination options acquired (in dollars per share)			16.63
Granted (in dollars per share)			0.00
Exercised (in dollars per share)			18.81
Forfeited (in dollars per share)			16.63
Expired (in dollars per share)			16.63
Outstanding at end of period (in dollars per share)	$ 16.63		16.63
Exercisable at end of period (in dollars per share)	$ 16.63		$ 16.63
Weighted Average Remaining Contractual Term
Outstanding at end of period			5 years 2 months 20 days
Exercisable at end of period			5 years 2 months 20 days
Aggregate Intrinsic Value ($000)
Outstanding at end of period	$ 352		$ 352
Exercisable at end of period	$ 269		$ 269