Stockholders' Equity - Summary of the Company's Actual Capital Amounts and Ratios (Detail) (Company [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
Company [Member]
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 269,044	$ 247,761
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	246,798	227,000
Tier 1 Capital (to 4th Qtr. Average Assets), Actual Amount	246,798	227,000
Total Capital (to Risk-Weighted Assets), Ratio	15.12%	14.92%
Tier 1 Capital (to Risk-Weighted Assets), Ratio	13.87%	13.67%
Tier 1 Capital (to 4th Qtr. Average Assets), Ratio	6.91%	6.50%
Total Capital (to Risk-Weighted Assets), Capital Adequacy Amount	142,366	132,870
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Amount	71,183	66,435
Tier 1 Capital (to 4th Qtr. Average Assets), Capital Adequacy Amount	142,930	139,769
Total Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	4.00%	4.00%
Tier 1 Capital (to 4th Qtr. Average Assets), Capital Adequacy Ratio	4.00%	4.00%
Total Capital (to Risk-Weighted Assets), Well Capitalized Amount	177,957	166,088
Tier 1 Capital (to Risk-Weighted Assets), Well Capitalized Amount	106,774	99,653
Tier 1 Capital (to 4th Qtr. Average Assets), Well Capitalized Amount	$ 178,663	$ 174,711
Total Capital (to Risk-Weighted Assets), Well Capitalized Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Well Capitalized Ratio	6.00%	6.00%
Tier 1 Capital (to 4th Qtr. Average Assets), Well Capitalized Ratio	5.00%	5.00%