Fair Value (Redeemable Noncontrolling Interest Activity) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2012
Fair Value [Abstract]
As of January 1, 2012		$ 235,909
Income allocated to redeemable noncontrolling interests	9,780	5,936
Distributions to redeemable noncontrolling interests		(6,289)
Increase in fair value of redeemable noncontrolling interests charged to additional paid-in capital		10,990
Balance, June 30, 2012	$ 246,546	$ 246,546

The portion of net income or loss for the period attributable to redeemable noncontrolling interest (if any) deducted in order to derive the portion attributable to the parent. This element should be used for redeemable noncontrolling interests that are classified within temporary equity.

No definition available.

Name:	us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration