Share-Based Payment Plans - Summary of options activity (Details) - Stock Options - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Options
Outstanding at beginning of year			916,425
Granted	0	0	0	0
Exercised			(65,200)
Forfeited			(1,500)
Outstanding at period end	849,725		849,725
Vested or expected to vest	849,725		849,725
Exercisable at period end	656,622		656,622
Weighted Average Exercise Price
Outstanding at beginning of year			$ 13.56
Granted			0
Exercised			12.50
Forfeited			24.90
Outstanding at period end	$ 13.62		13.62
Vested or expected to vest	13.62		13.62
Exercisable at period end	$ 13.09		$ 13.09
Weighted Average Remaining Contractual Life (Years), outstanding at period end			5 years 10 months 13 days
Weighted Average Remaining Contractual Life (Years), vested or expected to vest			5 years 10 months 13 days
Weighted Average Remaining Contractual Life (Years), exercisable at period end			5 years 8 months 4 days