Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue Recognition on contract basis
Total	100.00%	100.00%	100.00%
Time-and-material [Member]
Revenue Recognition on contract basis
Total	49.00%	49.00%	49.00%
Fixed-price [Member]
Revenue Recognition on contract basis
Total	30.00%	28.00%	28.00%
Cost-based [Member]
Revenue Recognition on contract basis
Total	21.00%	23.00%	23.00%