Capital Stock (Detail) - shares	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Stockholders Equity Note [Abstract]
Beginning balance	169,316,460	168,628,177
SARs exercised	0	77,002
Restricted stock grants	459,099	335,103
Restricted stock units vested	246,564	252,507
Treasury shares issued	13,772	23,671
Ending balance	170,035,895	169,316,460