Summary of Significant Accounting Policies - Narrative (Detail)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies [Line Items]
Maximum period to sell loans held for sale	45 days
Maximum contractual term	10 years
Expire period of warrant	10 years
Buildings [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of the asset	39 years
Maximum [Member]
Significant Accounting Policies [Line Items]
Fair values are subject to refinement maximum year	1 year
Maximum [Member] | Building Improvements [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of the asset	15 years
Maximum [Member] | Equipment [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of the asset	7 years
Minimum [Member] | Building Improvements [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of the asset	7 years
Minimum [Member] | Equipment [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of the asset	3 years