Related Party Transactions (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Related Party Transaction [Line Items]
Payments for life insurance policies			$ 94,000	$ 284,000
Management [Member] | Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]
Related Party Transaction [Line Items]
Estimated fair value of life insurance policies	9,000,000		9,000,000		8,700,000
Board of Directors Chairman [Member] | Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	94,000	284,000	94,000	284,000
Chief Executive Officer [Member] | Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	0	0	0	0
Related Customer [Member] | Management [Member]
Related Party Transaction [Line Items]
Charges to related party	153,000	137,000	287,000	259,000
Related party receivables	846,000		846,000		907,000
Related party revenues	305,000	262,000	601,000	607,000
Accounts receivable, related party	$ 1,414,000		$ 1,414,000		$ 1,232,000