Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Consolidated Balance Sheets [Abstract]
Allowance for accounts with partners		$ 7.6
Allowance for value added tax receivable	$ 4.7	$ 4.2
Preferred stock, shares authorized	500,000
Preferred stock, par value	$ 25
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	66,041,338	66,041,338
Treasury Stock Shares	7,545,977	7,514,169