diff --git a/azurerm/internal/services/maintenance/parse/maintenance_assignment.go b/azurerm/internal/services/maintenance/parse/maintenance_assignment.go
index 9025038228d5e..dacaff662addd 100644
--- a/azurerm/internal/services/maintenance/parse/maintenance_assignment.go
+++ b/azurerm/internal/services/maintenance/parse/maintenance_assignment.go
@@ -3,7 +3,6 @@ package parse
 import (
 	"fmt"
 	"regexp"
-	"strings"
 
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/helpers/azure"
 )
@@ -71,11 +70,11 @@ func TargetResourceID(input string) (TargetResourceId, error) {
 
 	id, err := azure.ParseAzureResourceID(input)
 	if err != nil {
-		return nil, fmt.Errorf("parsing target resource id %q: %+v", input, err)
+		return nil, fmt.Errorf("cannot parse target resource id %q: %+v", input, err)
 	}
 
 	if len(id.Path) != 1 && len(id.Path) != 2 {
-		return nil, fmt.Errorf("parsing target resource id %q", input)
+		return nil, fmt.Errorf("cannot parse target resource id %q: too many segments", input)
 	}
 
 	if len(id.Path) == 1 {
@@ -94,11 +93,9 @@ func TargetResourceID(input string) (TargetResourceId, error) {
 		}, nil
 	}
 
-	resourceId := strings.TrimPrefix(input, "/")
-	resourceId = strings.TrimSuffix(resourceId, "/")
-	groups := regexp.MustCompile(`^subscriptions/.+/resource[gG]roups/.+/providers/.+/(.+)/(.+)/(.+)/(.+)$`).FindStringSubmatch(resourceId)
+	groups := regexp.MustCompile(`^/subscriptions/[^/]+/resource[gG]roups/[^/]+/providers/[^/]+/([^/]+)/([^/]+)/([^/]+)/([^/]+)$`).FindStringSubmatch(input)
 	if len(groups) != 5 {
-		return nil, fmt.Errorf("parsing target resource id: %q", resourceId)
+		return nil, fmt.Errorf("cannot parse target resource id: %q", input)
 	}
 
 	return ScopeInResource{
diff --git a/website/docs/r/maintenance_assignment.html.markdown b/website/docs/r/maintenance_assignment.html.markdown
index 82210e2bc2d51..72a732a1b332b 100644
--- a/website/docs/r/maintenance_assignment.html.markdown
+++ b/website/docs/r/maintenance_assignment.html.markdown
@@ -96,9 +96,9 @@ The following arguments are supported:
 
 * `location` - (Required) Specified the supported Azure location where the resource exists. Changing this forces a new resource to be created.
 
-* `maintenance_configuration_id` - (Required) Specified the id of Maintenance Configuration Resource. Changing this forces a new resource to be created.
+* `maintenance_configuration_id` - (Required) Specified the ID of Maintenance Configuration Resource. Changing this forces a new resource to be created.
 
-* `target_resource_id` - (Required) Specified the target resource id where the Maintenance Configuration will be assigned to. Currently, only `Virtual Machine` and `Dedicated Host` resources are supported. Changing this forces a new resource to be created.
+* `target_resource_id` - (Required) Specified the target resource ID where the Maintenance Configuration will be assigned to. Currently, only `Virtual Machine` and `Dedicated Host` resources are supported. Changing this forces a new resource to be created.
 
 ## Attributes Reference