Acquisitions and Dispositions - Additional Information (Detail) (USD $)	1 Months Ended		3 Months Ended	6 Months Ended
	Apr. 30, 2013	Oct. 17, 2012 Subsidiary	Jun. 30, 2013	Jun. 30, 2013 Subsidiary	Dec. 31, 2012
Loans At Acquisition Date [Line Items]
Payment for equity interests	$ 57,500,000
Acquisition related expenses			(2,479,000)	(2,479,000)
Bargain purchase gain	10,044,000		10,044,000	10,044,000
Loans receivable not acquired by the company			6,287,551,000	6,287,551,000	5,582,767,000
Fair value of non-impaired loans acquired	242,600,000
Gross contractual amounts receivable	370,200,000
Number of wholly owned subsidiaries		2		11
Fair value of non-impaired loans acquired having evidence of credit deterioration	108,900,000
Gross contractual amounts receivable having evidence of credit deterioration	253,400,000
Outstanding credit card loans			27,645,000	27,645,000	31,124,000
Centennial [Member]
Loans At Acquisition Date [Line Items]
Combined assets	3,160,000,000
Combined deposits	2,760,000,000
Loans receivable not acquired by the company			12,700,000	12,700,000
Acquisition related costs				$ 1,200,000