Lease Commitments And Contingencies - Narrative (Detail) (USD $)	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Lease Commitments and Contingencies:
Aggregate future net minimum lease payments	$ 4,882,000
Lease expense	$ 632,000	$ 621,000

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717

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