Investment Securities - Company's Investments' Gross Unrealized Losses and Fair Value (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 6,321,000	$ 5,540,000
Less Than 12 Months, Unrealized Losses	26,000	5,000
12 Months or Longer, Fair Value	1,985,000	6,582,000
12 Months or Longer, Unrealized Losses	16,000	72,000
Total, Fair Value	8,306,000	12,122,000
Total, Unrealized Losses	42,000	77,000
Ginnie Mae and GSE Mortgage-Backed Pass-Through Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	6,321,000	5,540,000
Less Than 12 Months, Unrealized Losses	26,000	5,000
12 Months or Longer, Fair Value	24,000	4,563,000
12 Months or Longer, Unrealized Losses	1,000	38,000
Total, Fair Value	6,345,000	10,103,000
Total, Unrealized Losses	27,000	43,000
Ginnie Mae Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	1,961,000	2,019,000
12 Months or Longer, Unrealized Losses	15,000	34,000
Total, Fair Value	1,961,000	2,019,000
Total, Unrealized Losses	$ 15,000	$ 34,000