Investment Securities - Investment Securities by Credit Rating Type (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	$ 1,399,428,000		$ 1,520,237,000
Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	295,506,000		299,037,000
Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	854,503,000		891,189,000
Securities measured at fair value	1,788,000		1,858,000
Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	2,181,000		2,147,000
Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	63,359,000		70,243,000
Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	5,097,000		5,149,000
Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			37,702,000
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	18,575,000		18,346,000
Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	84,999,000		82,612,000
Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	25,487,000		25,546,000
Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	10,520,000		11,445,000
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	13,515,000		52,489,000
CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	25,686,000		24,332,000
Rated Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	1,399,428,000	[1]	1,520,237,000	[2]
Rated Securities [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	295,506,000		299,037,000
Rated Securities [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	854,503,000		891,189,000
Securities measured at fair value	1,788,000		1,858,000
Rated Securities [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	2,181,000		2,147,000
Rated Securities [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	63,359,000		70,243,000
Rated Securities [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	5,097,000		5,149,000
Rated Securities [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			37,702,000	[3]
Rated Securities [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	18,575,000		18,346,000
Rated Securities [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	84,999,000		82,612,000
Rated Securities [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	25,487,000		25,546,000
Rated Securities [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	10,520,000		11,445,000
Rated Securities [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	13,515,000
Rated Securities [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	25,686,000		24,332,000
AAA [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	67,022,000	[1]	73,261,000	[2]
AAA [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	8,140,000		8,168,000
AAA [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Securities measured at fair value	0		0
AAA [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AAA [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	53,785,000		59,944,000
AAA [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	5,097,000		5,149,000
AAA [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			0	[3]
AAA [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AAA [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AAA [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AAA [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AAA [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0
AAA [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	875,259,000	[1]	911,682,000	[2]
Split-rated AAA/AA Plus [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	854,503,000		891,189,000
Securities measured at fair value	1,788,000		1,858,000
Split-rated AAA/AA Plus [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	2,181,000		2,147,000
Split-rated AAA/AA Plus [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			0	[3]
Split-rated AAA/AA Plus [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	18,575,000		18,346,000
Split-rated AAA/AA Plus [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Split-rated AAA/AA Plus [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0
Split-rated AAA/AA Plus [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	140,534,000	[1]	141,083,000	[2]
AA Plus to AA- [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	137,718,000		138,256,000
AA Plus to AA- [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Securities measured at fair value	0		0
AA Plus to AA- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	58,000		68,000
AA Plus to AA- [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			0	[3]
AA Plus to AA- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
AA Plus to AA- [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	2,758,000
AA Plus to AA- [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	151,787,000	[1]	155,164,000	[2]
A Plus to A- [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	143,238,000		146,155,000
A Plus to A- [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Securities measured at fair value	0		0
A Plus to A- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	2,935,000		3,439,000
A Plus to A- [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			0	[3]
A Plus to A- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
A Plus to A- [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	5,614,000
A Plus to A- [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BBB Plus to BBB- [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	96,811,000	[1]	171,851,000	[2]
BBB Plus to BBB- [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	6,215,000		6,263,000
BBB Plus to BBB- [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Securities measured at fair value	0		0
BBB Plus to BBB- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BBB Plus to BBB- [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	3,410,000		3,595,000
BBB Plus to BBB- [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BBB Plus to BBB- [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			37,702,000	[3]
BBB Plus to BBB- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BBB Plus to BBB- [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	56,556,000		54,585,000
BBB Plus to BBB- [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	25,487,000		25,546,000
BBB Plus to BBB- [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BBB Plus to BBB- [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	5,143,000
BBB Plus to BBB- [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BB Plus and below [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	32,272,000	[1]	32,469,000	[2]
BB Plus and below [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	195,000		195,000
BB Plus and below [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Securities measured at fair value	0		0
BB Plus and below [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BB Plus and below [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	3,171,000		3,197,000
BB Plus and below [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BB Plus and below [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			0	[3]
BB Plus and below [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BB Plus and below [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	18,386,000		17,632,000
BB Plus and below [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
BB Plus and below [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	10,520,000		11,445,000
BB Plus and below [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0
BB Plus and below [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	35,743,000	[1]	34,727,000	[2]
Corporate Credit Quality Indicator Unrated [Member] | Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Residential mortgage-backed securities issued by GSEs
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Securities measured at fair value	0		0
Corporate Credit Quality Indicator Unrated [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Private label residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Private label commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014			0	[3]
Corporate Credit Quality Indicator Unrated [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	10,057,000		10,395,000
Corporate Credit Quality Indicator Unrated [Member] | Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0		0
Corporate Credit Quality Indicator Unrated [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	0
Corporate Credit Quality Indicator Unrated [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,361,998 at March 31, 2015 and $1,493,648 at December 31, 2014	$ 25,686,000		$ 24,332,000

[1] The Company uses the average credit rating of the combination of S&P, Moody’s, and Fitch, where ratings differ

[2] The Company uses the average credit rating of the combination of S&P, Moody’s, and Fitch, where ratings differ.

[3] At least 80% of mutual funds are investment grade corporate debt securities.