Schedule II Valuation and Qualifying Accounts (Details) - Allowance for Trade Receivables [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 3,838	$ 4,327	$ 3,045
Additions Charged to Costs and Expenses		1,459	896	1,413
Additions Recorded During Acquisitions		0	0	0
Deductions	[1]	1,426	1,385	130
Balance at End of Period		$ 3,871	$ 3,838	$ 4,327

[1] Accounts written off, net of recoveries.