Valuation And Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance For Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 7,680	$ 9,386	$ 12,127
Charged to costs and expenses	1,179	1,914	1,420
Deductions	2,787	3,620	4,161
Balance at end of period	6,072	7,680	9,386
Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	27,539	30,541	28,376
Charged to costs and expenses	0	2,239	2,243
Deductions	309	5,241	78
Balance at end of period	$ 27,230	$ 27,539	$ 30,541