Condensed consolidated statements of changes in shareholders' equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income, Net
Balance at Dec. 31, 2014	$ 215,228	$ 17,180	$ 94,544	$ 98,237	$ 5,267
Net income	38,665			38,665
Other comprehensive income, net of taxes	2,843				2,843
Cash dividends paid	(21,100)			(21,100)
Balance at Sep. 30, 2015	235,636	17,180	94,544	115,802	8,110
Balance at Dec. 31, 2015	236,674	17,180	94,544	122,493	2,457
Net income	31,581			31,581
Other comprehensive income, net of taxes	6,137				6,137
Common stock issued, net of offering costs	115,525	6,765	108,760
Conversion of cash-settled to stock-settled for, Equity based incentive plans	2,388		2,388
Conversion of cash-settled to stock-settled for, Deferred compensation plan	3,000		3,000
Stock based compensation expense	3,373		3,373
Restricted stock units vested and distributed, net of shares withheld for taxes	(270)	30	(300)
Cash dividends paid	(69,300)			(69,300)
Balance at Sep. 30, 2016	$ 329,108	$ 23,975	$ 211,765	$ 84,774	$ 8,594