Annual report pursuant to Section 13 and 15(d)

Quarterly Financial Information - Summary of Quarterly Results of Operations (Detail)

v2.4.1.9
Quarterly Financial Information - Summary of Quarterly Results of Operations (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]                      
Operating revenues $ 19,216us-gaap_RealEstateRevenueNet $ 19,014us-gaap_RealEstateRevenueNet $ 18,390us-gaap_RealEstateRevenueNet $ 17,136us-gaap_RealEstateRevenueNet $ 16,860us-gaap_RealEstateRevenueNet $ 16,190us-gaap_RealEstateRevenueNet $ 14,258us-gaap_RealEstateRevenueNet $ 14,035us-gaap_RealEstateRevenueNet $ 73,756us-gaap_RealEstateRevenueNet $ 61,343us-gaap_RealEstateRevenueNet $ 51,270us-gaap_RealEstateRevenueNet
Operating expenses 10,970us-gaap_OperatingExpenses 11,457us-gaap_OperatingExpenses 11,243us-gaap_OperatingExpenses 23,736us-gaap_OperatingExpenses 9,542us-gaap_OperatingExpenses 8,639us-gaap_OperatingExpenses 7,369us-gaap_OperatingExpenses 7,273us-gaap_OperatingExpenses 57,406us-gaap_OperatingExpenses 32,823us-gaap_OperatingExpenses 24,895us-gaap_OperatingExpenses
Other expense (2,082)us-gaap_NonoperatingIncomeExpense (7,328)us-gaap_NonoperatingIncomeExpense (5,928)us-gaap_NonoperatingIncomeExpense (6,914)us-gaap_NonoperatingIncomeExpense (6,984)us-gaap_NonoperatingIncomeExpense (7,242)us-gaap_NonoperatingIncomeExpense (6,438)us-gaap_NonoperatingIncomeExpense (6,329)us-gaap_NonoperatingIncomeExpense (22,252)us-gaap_NonoperatingIncomeExpense (26,993)us-gaap_NonoperatingIncomeExpense (22,614)us-gaap_NonoperatingIncomeExpense
Net income (loss) 6,164us-gaap_NetIncomeLoss 229us-gaap_NetIncomeLoss 1,219us-gaap_NetIncomeLoss (13,514)us-gaap_NetIncomeLoss 334us-gaap_NetIncomeLoss 309us-gaap_NetIncomeLoss 451us-gaap_NetIncomeLoss 433us-gaap_NetIncomeLoss (5,902)us-gaap_NetIncomeLoss 1,527us-gaap_NetIncomeLoss 3,761us-gaap_NetIncomeLoss
Dividends attributable to preferred and senior common stock (1,220)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,160)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,133)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,123)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,120)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,106)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,092)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (1,076)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (4,636)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (4,394)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock (4,206)good_BusinessAcquisitionProFormaDividendsAttributableToPreferredAndSeniorCommonStock
Net loss attributable to common stockholders $ 4,944us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (931)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 86us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (14,637)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (786)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (797)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (641)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (643)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (10,538)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (2,867)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (445)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Net income (loss) available to common stockholders - basic & diluted $ 0.36us-gaap_EarningsPerShareBasicAndDiluted $ (0.05)us-gaap_EarningsPerShareBasicAndDiluted $ 0.01us-gaap_EarningsPerShareBasicAndDiluted $ (0.93)us-gaap_EarningsPerShareBasicAndDiluted $ (0.05)us-gaap_EarningsPerShareBasicAndDiluted $ (0.06)us-gaap_EarningsPerShareBasicAndDiluted $ (0.05)us-gaap_EarningsPerShareBasicAndDiluted $ (0.06)us-gaap_EarningsPerShareBasicAndDiluted $ (0.61)us-gaap_EarningsPerShareBasicAndDiluted $ (0.22)us-gaap_EarningsPerShareBasicAndDiluted $ (0.04)us-gaap_EarningsPerShareBasicAndDiluted