Acquisitions: Percentage Ownership (Details)	Oct. 03, 2012	Oct. 26, 2012	Jun. 04, 2014	Oct. 24, 2013	Sep. 16, 2013	Nov. 14, 2014
FlatIron Crossing
Acquisition
Ownership percentage at completion of acquisition (as a percent)	100.00%
Fair value of existing ownership interest (as a percent)	25.00%
Arrowhead Towne Center
Acquisition
Ownership percentage at completion of acquisition (as a percent)		100.00%
Fair value of existing ownership interest (as a percent)		66.70%
Cascade Mall
Acquisition
Ownership percentage at completion of acquisition (as a percent)			100.00%
Superstition Springs Land I
Acquisition
Ownership percentage at completion of acquisition (as a percent)				100.00%
Fair value of existing ownership interest (as a percent)				66.70%
Camelback Colonnade
Acquisition
Ownership percentage at completion of acquisition (as a percent)					100.00%
Fair value of existing ownership interest (as a percent)					73.20%
PPRLP Queens Portfolio
Acquisition
Ownership percentage at completion of acquisition (as a percent)						100.00%
Fair value of existing ownership interest (as a percent)						51.00%