Stock-Based Compensation (PBRSU Weighted Average Assumptions) (Details) - PBRSU [Member]		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield		0.00%	0.00%
Risk-free interest rate	[1]	0.93%	0.74%
Expected volatility	[2]	24.01%	27.88%
Share-based Compensation Arrangement, Fair Value, Average Shareholder Return	[2]	8.37%	(0.90%)

[1] The risk-free interest rate for the periods within the contractual term of the PBRSUs is based on the U.S. Treasury yield curve in effect at the time of the grant.

[2] The expected volatility and average total stockholder return is a measure of the amount by which a stock price has fluctuated or is expected to fluctuate based primarily on our and our peers' historical data.