XML 90 R66.htm IDEA: XBRL DOCUMENT v2.4.0.6
Reconciliation Between Statutory Federal Income Tax Rate and Effective Income Tax Rate as Percentage of Income Before Income Taxes (Detail)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Income Tax Rate Reconciliation [Line Items]      
Income tax expense computed at the statutory federal income tax rate 35.00% 35.00% 35.00%
State taxes 1.00% 1.00% 1.00%
IRC Sec. 162(m) limitation 0.60% 0.30%  
Other (0.50%) (0.30%) 0.90%
Effective income tax rate 36.10% 36.00% 36.90%