Note 1. Principal Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Change in Accounting Estimate [Line Items]
Operating Income	$ 102,700	$ 76,299	$ 135,762	$ 107,898
Net income	53,667	42,897	66,560	56,902
Salvage Value [Member]
Change in Accounting Estimate [Line Items]
Operating Income	1,600		3,400
Net income	$ 1,000		$ 2,100
Earnings per common share, basic and diluted	$ 0.02		$ 0.04