Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in valuation and qualifying accounts
Balance at Beginning of Period	$ 81,514	$ 86,176	$ 83,324
Additions Charged to: Costs & Expenses	4,075	4,717	5,926
Additions Charged to: Other Accounts	3,425	3,427	6,941
Deductions	16,522	12,806	10,015
Balance at End of Period	72,492	81,514	86,176
Allowance for bad debts
Changes in valuation and qualifying accounts
Balance at Beginning of Period	2,281	2,750	3,957
Additions Charged to: Costs & Expenses	101	198	364
Additions Charged to: Other Accounts	125	28	64
Deductions	1,345	695	1,635
Balance at End of Period	1,162	2,281	2,750
Allowance for excess and obsolete inventory
Changes in valuation and qualifying accounts
Balance at Beginning of Period	21,535	20,431	25,834
Additions Charged to: Costs & Expenses	3,502	3,597	2,789
Additions Charged to: Other Accounts	1,506	495	188
Deductions	4,510	2,988	8,380
Balance at End of Period	22,033	21,535	20,431
Valuation allowance for deferred taxes
Changes in valuation and qualifying accounts
Balance at Beginning of Period	57,698	62,995	53,533
Additions Charged to: Costs & Expenses	472	922	2,773
Additions Charged to: Other Accounts	1,794	2,904	6,689
Deductions	10,667	9,123
Balance at End of Period	$ 49,297	$ 57,698	$ 62,995