(all) of a piece

of a piece: Belonging to the same class or kind. 

... Am-Heritage

(all) of a piece (slightly formal): sharing the same basic characteristics or ideas 

• Willner edited the music to make the different parts seem all of a piece.
  

Usage notes: often followed by with: 

• His attitude toward imagination was very much of a piece with his attitude toward existence.
  

... Cambridge-Am-Idioms

http://idioms.thefreedictionary.com/of+a+piece