It's a bit messy, but it gets the job done :-)
CREATE TABLE dbo.Documents (
Details VARCHAR(1000)
);
GO
INSERT INTO dbo.Documents
VALUES ('4-Documento d’identità-3-Attestato di Rischio-2-Carta di Circolazione'),
('10-Contrassegno'),
('12-Documenti di annullo polizza-10-Contrassegno'),
('10-Contrassegno'),
('12-Documenti di annullo polizza-10-Contrassegno');
SELECT CASE WHEN (FirstLine + SecondLine + ThirdLine) LIKE '%-'
THEN LEFT(FirstLine + SecondLine + ThirdLine, LEN(FirstLine + SecondLine + ThirdLine) -1)
ELSE (FirstLine + SecondLine + ThirdLine) END AS CleanData
FROM (
SELECT
LEFT(Details, CHARINDEX('-', Details)) AS FirstLine,
REPLACE(CASE
WHEN REPLACE( REPLACE( LEFT(Details,CHARINDEX('-', Details, CHARINDEX('-', Details )+1)+2) , LEFT(Details, CHARINDEX('-', Details, CHARINDEX('-', Details)+1)), ''), LEFT(Details, CHARINDEX('-', Details)), '') LIKE '%[0-9]' THEN REPLACE( REPLACE( LEFT(Details,CHARINDEX('-', Details, CHARINDEX('-', Details )+1)+2) , LEFT(Details, CHARINDEX('-', Details, CHARINDEX('-', Details)+1)), ''), LEFT(Details, CHARINDEX('-', Details)), '') + '-'
ELSE REPLACE( LEFT(Details,CHARINDEX('-', Details, CHARINDEX('-', Details )+1)+2) , LEFT(Details, CHARINDEX('-', Details, CHARINDEX('-', Details)+1)), '')
END , LEFT(Details, CHARINDEX('-', Details)), '') AS SecondLine,
CASE WHEN REVERSE(LEFT(REVERSE(Details), CHARINDEX('-', REVERSE(Details))+2)) LIKE '-%'
THEN LEFT(REVERSE(LEFT(REVERSE(Details), CHARINDEX('-', REVERSE(Details))+2)), 3) ELSE '' END AS ThirdLine
FROM dbo.Documents
) AS A;