Note 1. Principal Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Change in Accounting Estimate [Line Items]
Operating Income	$ 33,062	$ 31,599
Net income	12,893	14,005
Salvage Value [Member]
Change in Accounting Estimate [Line Items]
Operating Income	1,800
Net income	$ 1,100
Earnings per common share, basic and diluted	$ 0.02