Operating Segments (Financial Results By Operating Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financial results by operating segment
Net interest income (loss)	$ 21,370	$ 19,695	$ 41,533	$ 39,535
Provision for loan losses	1,729	10	3,505	4,385
Noninterest income	4,521	3,871	9,401	7,286
Noninterest expenses	15,155	15,268	30,458	31,264
Income before taxes	9,007	8,288	16,971	11,172
Taxes on income (loss)	3,189	2,876	5,874	3,891
Net income	5,818	5,412	11,097	7,281
Externally generated revenue from investing activities			2,300	1,900
Internally generated loss from fund management			900	1,000
Total loans at period end	1,971,634	1,821,377	1,971,634	1,821,377
Total assets at period end	2,572,935	2,402,262	2,572,935	2,402,262
Total deposits at period end	2,013,834	1,902,865	2,013,834	1,902,865
Oklahoma Banking [Member]
Financial results by operating segment
Net interest income (loss)	13,349	12,339	26,143	25,277
Provision for loan losses	1,424	(210)	2,846	50
Noninterest income	3,146	2,657	6,406	4,852
Noninterest expenses	9,735	9,879	19,432	19,839
Income before taxes	5,336	5,327	10,271	10,240
Taxes on income (loss)	1,892	1,837	3,555	3,566
Net income	3,444	3,490	6,716	6,674
Total loans at period end	1,193,108	1,085,986	1,193,108	1,085,986
Total assets at period end	1,228,506	1,130,161	1,228,506	1,130,161
Total deposits at period end	1,369,810	1,322,430	1,369,810	1,322,430
Texas Banking [Member]
Financial results by operating segment
Net interest income (loss)	6,197	5,640	12,285	11,206
Provision for loan losses	354	330	845	2,245
Noninterest income	466	290	922	592
Noninterest expenses	3,219	3,256	6,416	6,987
Income before taxes	3,090	2,344	5,946	2,566
Taxes on income (loss)	1,095	816	2,058	894
Net income	1,995	1,528	3,888	1,672
Total loans at period end	636,709	577,333	636,709	577,333
Total assets at period end	632,773	573,199	632,773	573,199
Total deposits at period end	196,390	190,475	196,390	190,475
Kansas Banking [Member]
Financial results by operating segment
Net interest income (loss)	1,614	1,638	3,172	3,466
Provision for loan losses	(52)	(113)	(186)	2,086
Noninterest income	290	300	592	618
Noninterest expenses	1,314	1,347	2,721	2,764
Income before taxes	642	704	1,229	(766)
Taxes on income (loss)	227	250	425	(267)
Net income	415	454	804	(499)
Total loans at period end	141,817	158,058	141,817	158,058
Total assets at period end	140,702	157,054	140,702	157,054
Total deposits at period end	156,383	135,585	156,383	135,585
Other Operations [Member]
Financial results by operating segment
Net interest income (loss)	210	78	(67)	(414)
Provision for loan losses	3	3		4
Noninterest income	619	624	1,481	1,224
Noninterest expenses	887	786	1,889	1,674
Income before taxes	(61)	(87)	(475)	(868)
Taxes on income (loss)	(25)	(27)	(164)	(302)
Net income	(36)	(60)	(311)	(566)
Total assets at period end	570,954	541,848	570,954	541,848
Total deposits at period end	$ 291,251	$ 254,375	$ 291,251	$ 254,375