Other Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Income And Expenses [Abstract]
Legal and professional fees	$ 135	$ 146	$ 315	$ 314
Printing and stockholder communications	46	150	109	160
Directors and Officers insurance	95	123	220	252
DERs expense	104	101	207	202
Amortization of restricted stock	20	79	41	158
Software implementation and maintenance	73	227	194	414
Administrative service fees	38	38	76	78
Rent	124	127	250	255
Stock exchange and filing fees	39	50	79	98
Custodian and clearing fees	60	63	130	122
Sarbanes-Oxley consulting fees	30	30	60	60
Commissions - Eurodollar Futures Contracts		15		44
Board of directors fees and expenses	79	74	157	151
Securities data services	103	100	223	200
Leasing commissions on rental properties	18	5	33	21
Other expenses on rental properties	63	63	113	139
Depreciation expense on rental properties	116	113	231	225
Property insurance on rental properties	28	28	56	56
Management fee for rental properties	45	41	89	83
Property taxes on rental properties	77	76	154	153
Other	40	41	79	74
Total of other expenses	$ 1,315	$ 1,690	$ 2,798	$ 3,259