Operating Segments (Financial Results By Operating Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financial results by operating segment
Net interest income (loss)	$ 19,805	$ 16,496	$ 59,340	$ 47,897
Provision (credit) for loan losses	1,713	23	6,098	(3,000)
Noninterest income	4,555	4,029	11,841	10,278
Noninterest expenses	16,156	14,077	47,420	41,141
Income before taxes	6,491	6,425	17,663	20,034
Taxes on income (loss)	2,236	2,303	6,127	7,216
Net income	4,255	4,122	11,536	12,818
Externally generated revenue from investing activities			2,400	1,400
Internally generated loss from fund management			900	1,700
Total loans at period end	1,880,112	1,548,094	1,880,112	1,548,094
Total assets at period end	2,468,042	2,059,899	2,468,042	2,059,899
Total deposits at period end	1,947,924	1,626,250	1,947,924	1,626,250
Oklahoma Banking [Member]
Financial results by operating segment
Net interest income (loss)	12,405	9,831	37,682	28,865
Provision (credit) for loan losses	1,531	(575)	1,581	(2,497)
Noninterest income	3,515	2,776	8,367	7,201
Noninterest expenses	10,539	8,015	30,378	23,058
Income before taxes	3,850	5,167	14,090	15,505
Taxes on income (loss)	1,322	1,852	4,888	5,584
Net income	2,528	3,315	9,202	9,921
Total loans at period end	1,117,716	832,282	1,117,716	832,282
Total assets at period end	1,161,386	847,436	1,161,386	847,436
Total deposits at period end	1,319,571	1,149,489	1,319,571	1,149,489
Texas Banking [Member]
Financial results by operating segment
Net interest income (loss)	5,541	5,589	16,747	15,602
Provision (credit) for loan losses	282	662	2,527	129
Noninterest income	340	584	932	1,171
Noninterest expenses	3,616	3,646	10,603	10,874
Income before taxes	1,983	1,865	4,549	5,770
Taxes on income (loss)	684	669	1,578	2,079
Net income	1,299	1,196	2,971	3,691
Total loans at period end	605,682	563,010	605,682	563,010
Total assets at period end	602,028	560,777	602,028	560,777
Total deposits at period end	187,234	205,115	187,234	205,115
Kansas Banking [Member]
Financial results by operating segment
Net interest income (loss)	1,574	1,551	5,040	4,745
Provision (credit) for loan losses	(99)	(69)	1,987	(637)
Noninterest income	294	304	912	935
Noninterest expenses	1,183	1,525	3,947	4,740
Income before taxes	784	399	18	1,577
Taxes on income (loss)	273	143	6	568
Net income	511	256	12	1,009
Total loans at period end	156,714	152,802	156,714	152,802
Total assets at period end	155,556	152,056	155,556	152,056
Total deposits at period end	144,856	122,961	144,856	122,961
Other Operations [Member]
Financial results by operating segment
Net interest income (loss)	285	(475)	(129)	(1,315)
Provision (credit) for loan losses	(1)	5	3	5
Noninterest income	406	365	1,630	971
Noninterest expenses	818	891	2,492	2,469
Income before taxes	(126)	(1,006)	(994)	(2,818)
Taxes on income (loss)	(43)	(361)	(345)	(1,015)
Net income	(83)	(645)	(649)	(1,803)
Total assets at period end	549,072	499,630	549,072	499,630
Total deposits at period end	$ 296,263	$ 148,685	$ 296,263	$ 148,685