Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 1,090	$ 1,194	$ 1,609
Additions, Charged to Income	826	1,157	1,129
Additions, Other Accounts	354	293	181
Deductions	(1,444)	(1,554)	(1,725)
Balance at End of Year	$ 826	$ 1,090	$ 1,194