Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Reconciliation of Weighted Average Common Shares Outstanding

A reconciliation of weighted average common shares outstanding used to calculate basic net income per common share and diluted net income per common share follows.

	2012	2011	2010
	(in thousands)
Weighted average common shares outstanding (basic)	199,067	198,912	190,860
Impact of common stock equivalents	972	746	537
Weighted average common shares outstanding (diluted)	200,039	199,658	191,397