Investments - Additional Details (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014 security	Dec. 31, 2013 security
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 150,117	$ 106,977
Number of Mortgage-Backed securities with unrealized losses	13	20
Number of Mortgage-backed securities	47	33
Par Value of Mortgage-backed securities pledged to FRB	138,458	103,049
Ginnie Mae
Schedule of Available-for-sale Securities [Line Items]
Number of Mortgage-Backed securities with unrealized losses	7
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	150,117	106,977
Mortgage-backed securities | Ginnie Mae
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	74,563
Mortgage-backed securities | Fannie Mae
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	68,435
Mortgage-backed securities | Freddie Mac
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 7,119