CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Tax benefit from exercise or vesting of equity awards, deferred tax asset deficiencies	$ 284	$ 83	$ 351
Cash dividends declared, per share	$ 0.12	$ 0.12	$ 0.12

The amount of tax deficiency associated with any equity-based compensation plan other than an employee stock ownership plan (ESOP) that is deducted from additional paid in capital. A tax deficiency results from the deductible amount for an award of an equity instrument on the entity's tax return being less than the cumulative compensation cost recognized for financial reporting purposes. This element should not be used to report tax deficiencies that are charged to income tax expense.

No definition available.

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