Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$ 28,192	$ 10,219
Finite-Lived Intangible Assets-Future Amortization Expense [Abstract]
2013	3,781
2014	2,732
2015	2,569
2016	2,311
2017	1,753
Thereafter	15,046
Goodwill [Roll Forward]
Goodwill, Gross	362,207	335,829
Goodwill, Accumulated Impairment	(228)	(228)
Goodwill, Net	361,979	335,601
Goodwill, Acquired During Period	26,378
Commercial [Member]
Goodwill [Roll Forward]
Goodwill, Gross	271,162	266,728
Goodwill, Accumulated Impairment	0	0
Goodwill, Net	271,162	266,728
Goodwill, Acquired During Period	4,434
Consumer [Member]
Goodwill [Roll Forward]
Goodwill, Gross	39,251	39,251
Goodwill, Accumulated Impairment	(228)	(228)
Goodwill, Net	39,023	39,023
Goodwill, Acquired During Period	0
Wealth Management [Member]
Goodwill [Roll Forward]
Goodwill, Gross	51,794	29,850
Goodwill, Accumulated Impairment	0	0
Goodwill, Net	51,794	29,850
Goodwill, Acquired During Period	21,944
Arizona [Member]
Goodwill [Roll Forward]
Goodwill, Net	16,422	16,422
Colorado [Member]
Goodwill [Roll Forward]
Goodwill, Net	77,555	55,611
New Mexico
Goodwill [Roll Forward]
Goodwill, Net	15,273	15,273
Oklahoma [Member]
Goodwill [Roll Forward]
Goodwill, Net	12,607	8,173
Texas [Member]
Goodwill [Roll Forward]
Goodwill, Net	240,122	240,122
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	109,417	109,417
Accumulated amortization	107,848	107,023
Finite-lived intangible assets, net	1,569	2,394
Finite-Lived Intangible Assets-Future Amortization Expense [Abstract]
2013	475
2014	432
2015	393
2016	247
2017	22
Thereafter	0
Core Deposits [Member] | Arizona [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	0	29
Core Deposits [Member] | Colorado [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	377	548
Core Deposits [Member] | Texas [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	1,192	1,817
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	38,191	17,291
Accumulated amortization	11,568	9,466
Finite-lived intangible assets, net	26,623	7,825
Finite-Lived Intangible Assets-Future Amortization Expense [Abstract]
2013	3,306
2014	2,300
2015	2,176
2016	2,064
2017	1,731
Thereafter	15,046
Other Intangible Assets [Member] | Colorado [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	15,976	1,487
Other Intangible Assets [Member] | Kansas/Missouri [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	790	790
Other Intangible Assets [Member] | Oklahoma [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$ 9,857	$ 5,548