CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income attributable to redeemable noncontrolling interest	$ 485	$ 256	$ 2,965

Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

No definition available.

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