Schedule II - Consolidated Valuation and Qualifying Accounts - K (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 4,799		$ 5,684		$ 8,753
Charged to costs and expenses	(1,129)		(187)		8,678
Transferred from (to) allowance for accounts / notes receivable	46		46		(101)
Deductions	1,167	[1]	(744)	[1]	(11,646)	[1]
Balance at end of period	4,883		4,799		5,684
Allowance for Notes Receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	208		254		7,950
Charged to costs and expenses	0		0		38
Transferred from (to) allowance for accounts / notes receivable	(46)		(46)		101
Deductions	0	[1]	0	[1]	(7,835)	[1]
Balance at end of period	$ 162		$ 208		$ 254

[1] Uncollectible accounts written off, net of recoveries and adjustments to estimates for the allowance accounts.