Annual report pursuant to Section 13 and 15(d)

Defined Contribution Plan - Additional Information (Detail)

v2.4.0.6
Defined Contribution Plan - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Defined Contribution Benefit Plans [Line Items]  
Maximum employee contribution to defined contribution benefit plans 60.00%
Maximum company match of participant contribution of eligible compensation per pay period 6.00%
Define contribution plan, contribution $ 1.3
After January 1, 2012
 
Defined Contribution Benefit Plans [Line Items]  
Maximum employee contribution to defined contribution benefit plans 50.00%
Employer matching contribution to employee contribution percentage 5.00%
First 3 Percent of Each Participant's Contributions
 
Defined Contribution Benefit Plans [Line Items]  
Employer matching contribution to employee contribution percentage 50.00%
Employee contribution percentage of eligible compensation 3.00%
Second 3 Percent of Each Participant's Contributions
 
Defined Contribution Benefit Plans [Line Items]  
Employer matching contribution to employee contribution percentage 25.00%
Employee contribution percentage of eligible compensation 3.00%