Note 1. Principal Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Change in Accounting Estimate [Line Items]
Operating income	$ 91,375	$ 67,675	$ 227,137	$ 175,573
Net income	45,583	30,557	112,143	87,459
Salvage Value [Member]
Change in Accounting Estimate [Line Items]
Operating income	1,500		4,900
Net income	$ 800		$ 2,900
Earnings per common share, basic and diluted	$ 0.01		$ 0.05