Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2015

Equity [Abstract]

Summary of Shares Repurchased

		2015		2014		2013
Purchase of Treasury Stock	$	250,000,000	$	375,000,000	$	500,000,000
Shares repurchased		5,967,313		6,373,718		7,855,419