Mortgage-Backed Securities - Additional Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended	9 Months Ended
Dec. 31, 2013	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Sep. 30, 2013 Agency Securities
Investments Classified By Contractual Maturity Date [Line Items]
Impairment of mortgage-backed securities	$ 8,102			$ 8,102
Contractual maturity of Company's agency securities, in years		15 years	30 years

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 34

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e25351-111560

Name:	us-gaap_ImpairmentOfInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration