That is the problem I was having. If I set ldap_idmap_range_size higher I got the errors I posted.
I set debug_level = 9 and found some more helpful information that lead to a resolution this morning. I'll include some more below to help anyone else who may have this problem.
The error on debug_level 9 was "(Thu Jul 31 08:01:43 2014) [sssd[be[
DOMAIN.EDU]]] [sdap_idmap_init] (0x0100): Range size does not divide evenly. Uppermost range will not be used"
The man page says "ldap_idmap_range_size ...If the range size does not divide evenly into the min and max values, it will create as many complete slices as it can." However from my error that appears to not always be true.
My max and min are
ldap_idmap_range_min = 200000
ldap_idmap_range_max = 2000200000
so max minus min gives 2000000000 and picking a ldap_idmap_range_size that divides evenly (800000) made my errors go away.