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 at beginning of period	$ 9,386		$ 12,127		$ 11,301
Charged to costs and expenses	1,914		1,420		7,157
Deductions	3,620	[1]	4,161	[1]	6,331	[1]
Balance at end of period	7,680		9,386		12,127
Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	30,541		28,376		24,595
Charged to costs and expenses	2,239		2,243		3,781
Deductions	5,241	[1]	78	[1]	0	[1]
Balance at end of period	$ 27,539		$ 30,541		$ 28,376

[1] Write-offs of amounts previously reserved.