Concentrations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Concentration Risk [Line Items]
Concentration Risk, Supplier	1
Supplier Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%
Sales Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	52.00%	49.00%
Sales Revenue | UNITED KINGDOM
Concentration Risk [Line Items]
Concentration risk, percentage	35.00%	36.00%
Sales Revenue | Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	23.00%	31.00%
Sales Revenue | Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%	18.00%
Sales Revenue | Customer Three
Concentration Risk [Line Items]
Concentration risk, percentage	8.00%
Sales Revenue | Customer Four
Concentration Risk [Line Items]
Concentration risk, percentage	7.00%
Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	27.00%	39.00%
Gross trade accounts receivable from continuing operations	12.3
Accounts Receivable | UNITED KINGDOM
Concentration Risk [Line Items]
Concentration risk, percentage	45.00%	63.00%
Accounts Receivable | Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%	28.00%
Accounts Receivable | Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	11.00%