Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance for doubtful accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Period	$ 3,827		$ 3,148		$ 3,294
Charged to Cost and Expense	1,171		1,635		763
Others (A)	148	[1]	56	[1]	322	[1]
Deductions (B)	1,938	[2]	1,012	[2]	1,231	[2]
Balance End of Period	3,208		3,827		3,148
Valuation allowance on deferred tax assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Period	4,657		5,288		3,786
Charged to Cost and Expense	363		531		469
Others	(326)		(1,162)		(1,033)
Balance End of Period	$ 4,694		$ 4,657		$ 5,288

[1] (A)Additions to allowance for doubtful accounts attributable to acquisitions.

[2] (B)Write-off of bad debts, net of recoveries.