Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.0.8
Significant Accounting Policies - Effects of Prior Period Errors in Condensed Consolidated Statements of Comprehensive Income (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Net income $ 141,950 $ 111,873 $ 403,985 $ 351,755 $ 463,962 $ 414,959 $ 292,883
Total comprehensive income 158,862 118,175 408,309 352,939      
As Previously Reported [Member]
             
Net income   117,779   359,309 477,190 412,578 299,215
Total comprehensive income   $ 124,081   $ 360,493