SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) (Allowance for Doubtful Accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Allowance for Doubtful Accounts [Member]
VALUATION AND QUALIFYING ACCOUNTS
Balance at the beginning of Period	$ 12,278	$ 11,461	$ 9,738	$ 9,394
Charged to Costs and Expenses	11,197	10,388	11,095
Net (Deductions) Recoveries	(9,381)	(9,571)	(9,372)
Balance at the end of Period	$ 14,094	$ 12,278	$ 11,461	$ 9,394