Operating Segments (Financial Results By Operating Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 09, 2015
Financial results by operating segment
Net interest income (loss)	$ 79,443	$ 67,417	$ 65,004
Provision (credit) for loan losses	4,769	(3,566)	(6,624)
Noninterest income	16,085	14,457	18,931
Noninterest expenses	63,246	58,240	56,912
Income before taxes	27,513	27,200	33,647
Taxes on income (loss)	9,809	9,793	12,617
Net income	17,704	17,407	21,030
Total loans at period end	1,877,132	1,779,429	1,399,991
Total assets at period end	2,475,392	2,357,022	1,214
Total goodwill at period end	13,545	13,467	1,942,034	$ 12,300
Total deposits at period end	1,946,018	1,884,105	1,533,999
Oklahoma Banking [Member]
Financial results by operating segment
Net interest income (loss)	50,590		38,846
Provision (credit) for loan losses	2,007		(2,561)
Noninterest income	11,576		9,030
Noninterest expenses	40,083		31,363
Income before taxes	20,076		19,074
Taxes on income (loss)	7,157		7,152
Net income	12,919		11,922
Total loans at period end	1,095,930		793,262
Total assets at period end	1,138,969		194
Total goodwill at period end	12,525		805,704	$ 12,300
Total deposits at period end	1,330,176		1,113,477
Texas Banking [Member]
Financial results by operating segment
Net interest income (loss)	22,697		19,187
Provision (credit) for loan losses	973		(3,640)
Noninterest income	1,273		1,594
Noninterest expenses	13,734		13,387
Income before taxes	9,263		11,034
Taxes on income (loss)	3,303		4,138
Net income	5,960		6,896
Total loans at period end	636,643		460,680
Total assets at period end	633,328		1,020
Total goodwill at period end	1,020		458,489
Total deposits at period end	195,603		224,634
Kansas Banking [Member]
Financial results by operating segment
Net interest income (loss)	6,694		9,469
Provision (credit) for loan losses	1,786		(425)
Noninterest income	1,202		1,576
Noninterest expenses	5,275		8,616
Income before taxes	835		2,854
Taxes on income (loss)	298		1,070
Net income	537		1,784
Total loans at period end	144,559		146,043
Total assets at period end	143,558
Total goodwill at period end			147,256
Total deposits at period end	147,823		110,901
Other Operations [Member]
Financial results by operating segment
Net interest income (loss)	(538)		(2,498)
Provision (credit) for loan losses	3		2
Noninterest income	2,034		6,731
Noninterest expenses	4,154		3,546
Income before taxes	(2,661)		685
Taxes on income (loss)	(949)		257
Net income	(1,712)		428
Externally generated revenue from investing activities	3,000	2,100	7,600
Internally generated loss from fund management	1,500	$ 2,800	3,300
Total loans at period end			6
Total assets at period end	559,537
Total goodwill at period end			530,585
Total deposits at period end	$ 272,416		$ 84,987