Seat Licenses And Other Intangible Assets (Components Of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Value	$ 7,858	$ 7,800
Accumulated Amortization	(1,393)	(1,183)
Net Value	6,465	6,617
Seat Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives	5 years	5 years
Gross Value	2,266	2,072
Accumulated Amortization	(661)	(558)
Net Value	1,605	1,514
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives	8 years	8 years
Gross Value	5,400	5,400
Accumulated Amortization	(1,125)	(956)
Net Value	4,275	4,444
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives	15 years	15 years
Gross Value	2,400	2,400
Accumulated Amortization	(267)	(227)
Net Value	2,133	2,173
Domain Name [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives	15 years
Gross Value	58
Accumulated Amortization	(1)
Net Value	$ 57