Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Period		$ 2,989	$ 3,208	$ 3,827
Charged to Costs and Expenses		2,635	1,694		$ 1,171
Others	[1]	19	96		148
Deductions	[2]	(1,520)	(2,009)		(1,938)
Balance End of Period		4,123	2,989	3,208	3,827
Valuation allowance on deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Period		11,122	4,694	4,657
Charged to Costs and Expenses		269	281	363
Deductions		(7,248)		(326)
Others			6,147
Balance End of Period		$ 4,143	$ 11,122	$ 4,694	$ 4,657

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

[2] (B)Recoveries and write-off of bad debts.