Goodwill and Other Intangible Assets - Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 111,282	$ 112,172
Accumulated Amortization	(76,692)	(75,538)
Valuation Allowance	(404)	(504)
Net Intangible Assets	34,186	36,130
Loan Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	71,496	71,100
Accumulated Amortization	(46,668)	(45,032)
Valuation Allowance	(404)	(504)
Net Intangible Assets	24,424	25,564
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	35,194	35,194
Accumulated Amortization	(27,922)	(27,238)
Valuation Allowance	0	0
Net Intangible Assets	7,272	7,956
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	4,592	5,878
Accumulated Amortization	(2,102)	(3,268)
Valuation Allowance	0	0
Net Intangible Assets	$ 2,490	$ 2,610