Operating Segments (Financial Results By Operating Segment) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financial results by operating segment
Net interest income	$ 65,004,000	$ 62,650,000	$ 76,563,000
Provision for loan losses	(6,624,000)	(7,209,000)	3,107,000
Noninterest income	18,931,000	13,643,000	15,936,000
Noninterest expenses	56,912,000	55,311,000	63,322,000
Income (loss) before taxes	33,647,000	28,191,000	26,070,000
Taxes on income	12,617,000	10,756,000	9,883,000
Net income (loss)	21,030,000	17,435,000	16,187,000
Total loans at period end	1,399,991,000	1,270,903,000	1,378,735,000
Total assets at period end	1,942,034,000	1,981,423,000	2,122,255,000
Total deposits at period end	1,533,999,000	1,584,086,000	1,709,578,000
Oklahoma Banking [Member]
Financial results by operating segment
Net interest income	38,090,000	34,725,000	37,954,000
Provision for loan losses	(2,537,000)	(486,000)	448,000
Noninterest income	6,885,000	6,943,000	7,697,000
Noninterest expenses	29,086,000	28,000,000	29,406,000
Income (loss) before taxes	18,426,000	14,154,000	15,797,000
Taxes on income	6,909,000	5,400,000	5,989,000
Net income (loss)	11,517,000	8,754,000	9,808,000
Total loans at period end	772,710,000	681,991,000	652,121,000
Total assets at period end	781,647,000	686,736,000	664,607,000
Total deposits at period end	1,109,613,000	1,113,715,000	1,254,348,000
Texas Banking [Member]
Financial results by operating segment
Net interest income	19,187,000	18,949,000	25,190,000
Provision for loan losses	(3,640,000)	(6,403,000)	5,364,000
Noninterest income	1,594,000	1,305,000	1,854,000
Noninterest expenses	13,387,000	9,494,000	12,848,000
Income (loss) before taxes	11,034,000	17,163,000	8,832,000
Taxes on income	4,138,000	6,548,000	3,348,000
Net income (loss)	6,896,000	10,615,000	5,484,000
Total loans at period end	460,680,000	366,697,000	520,481,000
Total assets at period end	458,489,000	361,058,000	515,675,000
Total deposits at period end	224,634,000	207,227,000	166,919,000
Kansas Banking [Member]
Financial results by operating segment
Net interest income	9,469,000	10,527,000	9,685,000
Provision for loan losses	(425,000)	(472,000)	(2,705,000)
Noninterest income	1,576,000	1,944,000	2,440,000
Noninterest expenses	8,616,000	11,898,000	13,767,000
Income (loss) before taxes	2,854,000	1,045,000	1,063,000
Taxes on income	1,070,000	399,000	403,000
Net income (loss)	1,784,000	646,000	660,000
Total loans at period end	146,043,000	198,992,000	174,451,000
Total assets at period end	147,256,000	203,631,000	178,291,000
Total deposits at period end	110,901,000	247,884,000	270,368,000
Mortgage Banking [Member]
Financial results by operating segment
Net interest income	756,000	670,000	1,370,000
Provision for loan losses	(24,000)	148,000
Noninterest income	2,145,000	2,701,000	2,771,000
Noninterest expenses	2,277,000	2,287,000	2,430,000
Income (loss) before taxes	648,000	936,000	1,711,000
Taxes on income	243,000	357,000	649,000
Net income (loss)	405,000	579,000	1,062,000
Total loans at period end	20,552,000	23,215,000	31,682,000
Total assets at period end	24,057,000	26,162,000	34,304,000
Total deposits at period end	3,864,000	1,895,000	2,420,000
Other Operations [Member]
Financial results by operating segment
Net interest income	(2,498,000)	(2,221,000)	2,364,000
Provision for loan losses	2,000	4,000
Noninterest income	6,731,000	750,000	1,174,000
Noninterest expenses	3,546,000	3,632,000	4,871,000
Income (loss) before taxes	685,000	(5,107,000)	(1,333,000)
Taxes on income	257,000	(1,948,000)	(506,000)
Net income (loss)	428,000	(3,159,000)	(827,000)
Externally generated revenue from investing activities	7,600,000	1,600,000	800,000
Internally generated loss from fund management	3,300,000	100,000	2,800,000
Total loans at period end	6,000	8,000
Total assets at period end	530,585,000	703,836,000	729,378,000
Total deposits at period end	$ 84,987,000	$ 13,365,000	$ 15,523,000