Inventories (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Inventory, Net [Abstract]
Finished goods	$ 64,010,000	$ 59,409,000
Raw materials	32,983,000	30,485,000
Service parts	13,156,000	13,412,000
Work in process	19,000	316,000
Inventories	110,168,000	103,622,000
Service parts inventories not expected to be sold within next 12 months	$ 3,900,000	$ 4,300,000