Annual report pursuant to Section 13 and 15(d)

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Parenthetical) (Detail)

v2.4.1.9
Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Parenthetical) (Detail) (Restricted Stock [Member], Non-employee directors [Member])
12 Months Ended
Dec. 31, 2014
Restricted Stock [Member] | Non-employee directors [Member]
 
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]  
Restricted common stock issued, vesting period 3 years