Changes in Unrecognized Tax Benefit (Including Interest and Penalties) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits [Line Items]
Beginning Balance	$ 430
Additions based on tax positions related to current year	272
Additions for tax positions for prior years	176
Reduction for tax positions for prior years	(8)
Reduction as a result of a lapse of the applicable statute of limitations	(90)
Ending Balance	780
Reconciliation of Unrecognized Tax Benefit
Reconciliation of Unrecognized Tax Benefits [Line Items]
Beginning Balance	296
Additions based on tax positions related to current year	272
Additions for tax positions for prior years	136
Reduction for tax positions for prior years	(6)
Reduction as a result of a lapse of the applicable statute of limitations	(58)
Ending Balance	640
Interest & Penalties
Reconciliation of Unrecognized Tax Benefits [Line Items]
Beginning Balance	134
Additions for tax positions for prior years	40
Reduction for tax positions for prior years	(2)
Reduction as a result of a lapse of the applicable statute of limitations	(32)
Ending Balance	$ 140