Operating Segments (Financial Results By Operating Segment) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015
Financial results by operating segment
Net interest income (loss)	$ 19,695	$ 15,791		$ 39,535	$ 31,401
Provision (credit) for loan losses	10	(1,136)	$ (3,023)	4,385	(3,023)
Noninterest income	3,871	3,409		7,286	6,249
Noninterest expenses	15,268	13,982		31,264	27,064
Income before taxes	8,288	6,354		11,172	13,609
Taxes on income (loss)	2,876	2,193		3,891	4,913
Net income	5,412	4,161		7,281	8,696
Externally generated revenue from investing activities				1,900	700
Internally generated loss from fund management				1,000	1,000
Total loans at period end	1,821,377	1,449,430	$ 1,449,430	1,821,377	1,449,430
Total assets at period end	2,402,262	2,031,581		2,402,262	2,031,581
Total deposits at period end	1,902,865	1,624,446		1,902,865	1,624,446
Oklahoma Banking [Member]
Financial results by operating segment
Net interest income (loss)	12,339	9,299		25,277	19,034
Provision (credit) for loan losses	(210)	(689)		50	(1,922)
Noninterest income	2,657	2,386		4,852	4,425
Noninterest expenses	9,879	7,698		19,839	15,043
Income before taxes	5,327	4,676		10,240	10,338
Taxes on income (loss)	1,837	1,609		3,566	3,732
Net income	3,490	3,067		6,674	6,606
Total loans at period end	1,085,986	810,368		1,085,986	810,368
Total assets at period end	1,130,161	824,073		1,130,161	824,073
Total deposits at period end	1,322,430	1,134,020		1,322,430	1,134,020
Texas Banking [Member]
Financial results by operating segment
Net interest income (loss)	5,640	4,793		11,206	10,013
Provision (credit) for loan losses	330	(283)		2,245	(533)
Noninterest income	290	278		592	587
Noninterest expenses	3,256	3,793		6,987	7,228
Income before taxes	2,344	1,561		2,566	3,905
Taxes on income (loss)	816	531		894	1,410
Net income	1,528	1,030		1,672	2,495
Total loans at period end	577,333	493,047		577,333	493,047
Total assets at period end	573,199	491,442		573,199	491,442
Total deposits at period end	190,475	226,498		190,475	226,498
Kansas Banking [Member]
Financial results by operating segment
Net interest income (loss)	1,638	1,731		3,466	3,194
Provision (credit) for loan losses	(113)	(165)		2,086	(568)
Noninterest income	300	329		618	631
Noninterest expenses	1,347	1,606		2,764	3,215
Income before taxes	704	619		(766)	1,178
Taxes on income (loss)	250	216		(267)	425
Net income	454	403		(499)	753
Total loans at period end	158,058	146,015		158,058	146,015
Total assets at period end	157,054	147,302		157,054	147,302
Total deposits at period end	135,585	126,671		135,585	126,671
Other Operations [Member]
Financial results by operating segment
Net interest income (loss)	78	(32)		(414)	(840)
Provision (credit) for loan losses	3	1		4
Noninterest income	624	416		1,224	606
Noninterest expenses	786	885		1,674	1,578
Income before taxes	(87)	(502)		(868)	(1,812)
Taxes on income (loss)	(27)	(163)		(302)	(654)
Net income	(60)	(339)		(566)	(1,158)
Total assets at period end	541,848	568,764		541,848	568,764
Total deposits at period end	$ 254,375	$ 137,257		$ 254,375	$ 137,257