XML 90 R71.htm IDEA: XBRL DOCUMENT v3.3.1.900
Loans (Investment in Loans Related to Allowance for Loan Loss by Portfolio Segment Disaggregated Based on Impairment Methodology) (Detail) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Commercial and industrial $ 4,120,522 $ 4,055,225
Energy 1,758,195 1,773,945
Commercial Real Estate 4,292,727 3,915,877
Consumer Real Estate 880,749 849,051
Consumer and Other 434,338 393,437
Total loans 11,486,531 10,987,535
Loans Individually Evaluated for Impairment [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Commercial and industrial 22,860 31,860
Energy 21,139 636
Commercial Real Estate 32,994 20,499
Consumer Real Estate 485 596
Consumer and Other 0 0
Total loans 77,478 53,591
Loans Collectively Evaluated for Impairment [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Commercial and industrial 4,097,662 4,023,365
Energy 1,737,056 1,773,309
Commercial Real Estate 4,259,733 3,895,378
Consumer Real Estate 880,264 848,455
Consumer and Other 434,338 393,437
Total loans $ 11,409,053 $ 10,933,944