Employee Retirement Plans (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Actual employer contributions to defined benefit plans	$ 1.6	$ 7.4	$ 4.7	$ 15.5
Expected full year contributions by the employer to defined benefit plans			4.8
Contributions to multiemployer plan	$ 0.6	$ 0.6	1.7	$ 1.9
Expected full year contributions by the employer to the multiemployer plan			$ 2.3