Consolidated Balance Sheet (Parenthetical) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts receivable, current	$ 9,574,000	$ 10,037,000
4.5% Mandatory Convertible Preferred Stock, Par or Stated Value Per Share (dollars per share)	$ 0.01	$ 0.01
4.5% Mandatory Convertible Preferred Stock, Shares Authorized	20,000,000	20,000,000
4.5% Mandatory Convertible Preferred Stock, shares issued	9,775,000	9,775,000
4.5% Mandatory Convertible Preferred Stock, shares outstanding	9,775,000	9,775,000
Mandatory redemption and aggregate liquidation value, 4.5% Mandatory Convertible Preferred Stock	$ 977,500,000	$ 977,500,000
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	333,771,660	333,856,632
Common stock, shares outstanding	333,771,660	333,856,632