Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified					3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Level 1 [Member]	Dec. 31, 2012 Level 1 [Member]	Mar. 31, 2013 Recurring [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes payable (in hundredths)			106.85%	107.88%
Current and Non-Current Investments [Abstract]
Balance, beginning of period						$ 56
Unrealized gain (loss)						(47)
Realized gain (loss)						0
Balance, end of period						9
Balance, beginning of period							2,016
Unrealized gain (loss)							(441)
Realized gain (loss)							0
Balance, end of period							1,575
Balance, beginning of period								553
Unrealized gain (loss)								0
Realized gain (loss)								(88)
Balance, end of period								465
Balance, beginning of period					2,625
Unrealized gain (loss)					(488)
Realized gain (loss)					(88)
Balance, end of period					2,049
Components of accumulated other comprehensive income [Abstract]
Cumulative translation adjustment	1,983	1,965
Unrealized loss on available-for-sale security, net of tax	(445)	(398)
Accumulated other comprehensive income	$ 1,538	$ 1,567