Investment Securities - Investment Securities by Credit Rating Type (Detail) - USD ($)		Dec. 31, 2015		Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		$ 1,982,523,000		$ 1,520,237,000
Municipal obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		334,830,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		1,170,221,000		891,189,000
Securities measured at fair value		1,481,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		19,114,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		257,128,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		4,691,000		5,149,000
Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				18,346,000
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		2,993,000
Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		111,236,000		82,612,000
Trust preferred securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		24,314,000		25,546,000
Collateralized debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		10,060,000		11,445,000
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		13,251,000		52,489,000
CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		34,685,000		24,332,000
Rated Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		1,982,523,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		334,830,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		1,170,221,000		891,189,000
Securities measured at fair value		1,481,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		19,114,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		257,128,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		4,691,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			37,702,000
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				18,346,000
Rated Securities [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		2,993,000
Rated Securities [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		111,236,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		24,314,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		10,060,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		13,251,000
Rated Securities [Member] | CRA investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		34,685,000		24,332,000
AAA [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		248,245,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		7,949,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		235,605,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		4,691,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			0
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				0
AAA [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		0
AAA [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		1,192,328,000	[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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		1,170,221,000		891,189,000
Securities measured at fair value		1,481,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		19,114,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			0
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				18,346,000
Split-rated AAA/AA Plus [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		2,993,000
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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		183,221,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		180,460,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		40,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			0
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				0
AA Plus to AA- [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		2,721,000
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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		139,785,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		131,110,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		3,186,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			0
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				0
A Plus to A- [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		5,489,000
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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		117,303,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		6,243,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		1,750,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			37,702,000
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				0
BBB Plus to BBB- [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		79,955,000		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		24,314,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		5,041,000
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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		36,600,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		180,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		2,705,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			0
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				0
BB Plus and below [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		23,655,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		10,060,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		65,041,000	[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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		8,888,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		13,842,000		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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014	[3]			0
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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014				0
Corporate Credit Quality Indicator Unrated [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities - AFS, at fair value; amortized cost of $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		7,626,000		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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 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 $1,966,034 at December 31, 2015 and $1,493,648 at December 31, 2014		$ 34,685,000		$ 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.