Note 4. Fair-Value Measurements Financial Assets Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Cash equivalents	$ 375,586	$ 385,548
Marketable securities	8,285	8,285
Fair Value, Inputs, Level 1
Cash equivalents	63,092	63,092
Marketable securities	0	0
Fair Value, Inputs, Level 2
Cash equivalents	312,494	322,456
Marketable securities	8,285	8,285
Fair Value, Inputs, Level 3
Cash equivalents	0	0
Marketable securities	$ 0	$ 0