XML 85 R103.htm IDEA: XBRL DOCUMENT v2.4.1.9
Subsequent Event - Additional Information (Detail) (USD $)
3 Months Ended 12 Months Ended 0 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jan. 26, 2015
Subsequent Event [Line Items]                        
Dividends declared $ 0.38us-gaap_CommonStockDividendsPerShareDeclared $ 0.38us-gaap_CommonStockDividendsPerShareDeclared $ 0.38us-gaap_CommonStockDividendsPerShareDeclared $ 0.38us-gaap_CommonStockDividendsPerShareDeclared $ 0.36us-gaap_CommonStockDividendsPerShareDeclared $ 0.36us-gaap_CommonStockDividendsPerShareDeclared $ 0.36us-gaap_CommonStockDividendsPerShareDeclared $ 0.36us-gaap_CommonStockDividendsPerShareDeclared $ 1.52us-gaap_CommonStockDividendsPerShareDeclared $ 1.44us-gaap_CommonStockDividendsPerShareDeclared $ 1.24us-gaap_CommonStockDividendsPerShareDeclared  
Subsequent Event | Dividend Declared                        
Subsequent Event [Line Items]                        
Dividends declared                       $ 0.38us-gaap_CommonStockDividendsPerShareDeclared
/ us-gaap_DividendsAxis
= us-gaap_DividendDeclaredMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
Dividend payable date                       Mar. 06, 2015
Dividend payable, stockholders of record date                       Feb. 19, 2015
Dividend announcement date                       Jan. 26, 2015