Noncontrolling Interests (Redeemable Preferred Units) (Narrative) (Details) - Series Four Preferred Units [Member] - Noncontrolling Interests [Member] - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 25, 2015	May. 15, 2015	Feb. 17, 2015	Nov. 05, 2014	Oct. 16, 2014	Jul. 03, 2014	May. 19, 2014
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Preferred Units Liquidation Preference	$ 50.00
Series Four Preferred Units Released from Escrow (in shares)						27,773		319,687
Series Four Preferred Units Redeemed (in shares)		12,667
Redemption of Series Four Preferred Units		$ 0.6			$ 1.4		$ 16.0
Distributions to Series Four Preferred Units (in dollars per share)			$ 0.25	$ 0.25
Series Four Preferred Units Annual Dividend Payable Rate	2.00%