Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Percentage of income attributable to wholly-owned operations and investments for which income tax expense and effective tax rate calculated	100.00%
Valuation allowance	$ 391	$ 423
State and other net operating loss carry forwards	8,288
Gross unrecognized tax benefits	2,474	2,424	1,889
Unrecognized tax benefits that, if recognized, would affect the effective tax rate	1,609	1,773
Estimated accrued interest and penalties resulting from unrecognized tax benefits	$ 583	$ 495
Minimum
Income Taxes [Line Items]
State and other net operating loss carry forwards expiration date	2013
Maximum
Income Taxes [Line Items]
State and other net operating loss carry forwards expiration date	2026

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards.

+ References+ Details

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized expected to be realized or consumed after one year (or the normal operating cycle, if longer).

+ References+ Details

- Definition

This element represents the total of accruals as of the date of the statement of financial position for interest recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity and the amount of statutory penalties for a tax position claimed or expected to be claimed by the entity, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

+ References+ Details