Non Controlling Interests In the Parent Company Non Controlling Interests In the Parent Company (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Noncontrolling Interest [Abstract]
Aggregate amount related to non-controlling interests classified within equity	$ 21.0	$ 21.2
Settlement Value Of Non Controlling Interest In Operating Partnership	$ 27.4	$ 22.5

Carrying amount of the equity interests owned by noncontrolling partners in an operating partnership included in the entity's consolidated financial statements.

No definition available.

Name:	us-gaap_MinorityInterestInOperatingPartnerships
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant