Employee Retirement Plans (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]
Actual employer contributions to defined benefit plans	$ 7.4	$ 4.1	$ 15.5	$ 11.7
Expected full year contributions by the employer to defined benefit plans			16.2
Contributions to multiemployer plan	$ 0.6		1.9
Expected full year contributions by the employer to the multiemployer plan			$ 2.3