Earnings Per Share - Reconciliation of Basic and Diluted Weighted - Average Shares Outstanding (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Basic weighted average shares outstanding	125,816,943	131,491,182	126,465,420	132,322,704
Weighted average dilutive options outstanding	1,622,698	1,823,640	1,553,309	1,856,496
Diluted weighted average shares outstanding	127,439,641	133,314,822	128,018,729	134,179,200
Antidilutive shares	0	0	0	0