Employee Benefit Plans (Details) - Officer and Employee Plans [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Number
Shares, Outstanding	817,414	483,629
Shares, Granted	0	52,689
Shares, Exercised	(89,556)	(24,292)
Shares, Share conversion		23,468
Shares, Retained by Cornerstone shareholders in merger		285,209
Shares, Forfeited	(10,334)	(3,289)
Shares, Outstanding	717,524	817,414
Weighted Average Exercisable Price
Weighted Average Exercisable Price, Outstanding (in dollars per share)	$ 10.62	$ 10.20
Weighted Average Exercisable Price Granted (in dollars per share)	0.00	15.05
Weighted Average Exercisable Price Exercised (in dollars per share)	8.98	8.79
Weighted Average Exercisable Price, Share conversion (in dollars per share)		9.71
Weighted Average Exercisable Price, Retained by Cornerstone shareholders in merger (in dollars per share)		11.22
Weighted Average Exercisable Price Forfeited (in dollars per share)	28.49	10.83
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 10.57	$ 10.62