Noncontrolling Interests (Redeemable Preferred Units) (Narrative) (Details) (Noncontrolling Interests [Member], USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 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]
Series Four Preferred Units (in shares)	12,667
Series Four Preferred Units [Member]
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
Redemption of Series Four Preferred Units			$ 1.4		$ 16.0
Distributions to Series Two Preferred Units (in dollars per share)		$ 0.25
Series Four Preferred Units (in shares)	12,667				12,667
Series Four Preferred Units Annual Dividend Payable Rate	2.00%