Consolidated Statements Of Cash Flows (Parenthetical)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Cash Flows [Abstract]
Vesting period related to restricted stock awards, minimum (years)	3	3	3
Vesting period related to restricted stock awards, maximum (years)	7	7	7

The maximum vesting term over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriodMaximum
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration