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Significant Accounting Policies Significant Accounting Policies (Schedule of Real Estate Inventory) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Inventory Disclosure [Abstract]    
Completed home inventory and residential lots held for sale $ 47,048grbk_InventoryFinishedHomesandLandHeldforSale $ 33,950grbk_InventoryFinishedHomesandLandHeldforSale
Work in process 203,756grbk_InventoryHomesunderConstructionandLandunderDevelopment 140,325grbk_InventoryHomesunderConstructionandLandunderDevelopment
Undeveloped land 16,220us-gaap_InventoryOperativeBuildersOther 54,502us-gaap_InventoryOperativeBuildersOther
Land not owned under option agreements 7,279us-gaap_LandUnderPurchaseOptionsRecorded 0us-gaap_LandUnderPurchaseOptionsRecorded
Inventory, Real Estate $ 274,303us-gaap_InventoryOperativeBuilders $ 228,777us-gaap_InventoryOperativeBuilders