Fair Value of Financial Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value
Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value
Contingent Consideration
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value	1,985	959
Contingent Consideration | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value
Contingent Consideration | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value
Contingent Consideration | Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value	1,985	959
Penalty Payment Derivative
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value	238	138
Penalty Payment Derivative | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value
Penalty Payment Derivative | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value
Penalty Payment Derivative | Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities, fair value	$ 238	$ 138