Note Payable (Narratives) (Details) (NXT Loan, USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 17, 2010
Debt Instrument [Line Items]
Maximum borrowing capacity of loan					$ 30,000,000
Remaining borrowing capacity for loan	10,000,000		10,000,000
Cash paid for interest expense on notes payable	$ 155,000	$ 352,000	$ 508,000	$ 698,000
Maximum
Debt Instrument [Line Items]
Interest rate on loan (percent)	7.25%		7.25%
LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate loan (percent)	3.25%		3.25%