Quarterly report pursuant to Section 13 or 15(d)

Significant Accounting Policies - Effects of Prior Period Errors in Consolidated Statements of Comprehensive Income (Detail)

v2.4.0.8
Significant Accounting Policies - Effects of Prior Period Errors in Consolidated Statements of Comprehensive Income (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Net income $ 143,162 $ 131,951 $ 262,035 $ 239,882 $ 463,962 $ 414,959 $ 292,883
Total comprehensive income 140,590 117,336 249,447 234,764      
As Previously Reported [Member]
             
Net income   133,368   241,530 477,190 412,578 299,215
Total comprehensive income   $ 118,753   $ 236,412