1
general::
An average or normal amount; just what one might expect. For example, I missed three questions, but that's par for the course. This term comes from golf, where it refers to the number of strokes needed by an expert golfer to finish the entire course. Its figurative use for other kinds of expectation dates from the second half of the 1900s.
American Heritage Idioms
2
general::
Phrase(s): par for the course
typical; about what one could expect. (This refers to golf courses, not school courses.) • So he went off and left you? Well that’s about par for the course. He’s no friend. • I worked for days on this proposal, but it was rejected. That’s par for the course around here.
McGrawhill's American Idioms And Phrasal Verbs