Employee Benefit Plans (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Defined benefit plans:
Multiemployer pension plans	$ 5,699,000	$ 4,479,000	$ 8,515,000	$ 7,774,000
Defined contribution pension plans	4,070,000	3,485,000	8,821,000	8,434,000
U. S. Plans
Defined benefit plans:
Service cost	642,000	471,000	1,283,000	943,000
Interest cost	2,944,000	3,203,000	5,884,000	6,411,000
Expected return on plan assets	(3,913,000)	(3,899,000)	(7,822,000)	(7,806,000)
Recognized prior service costs	35,000	47,000	72,000	95,000
Recognized loss	1,264,000	1,155,000	2,526,000	2,313,000
Amortization of transition liability			0	0
Settlement/curtailment gains	0	0	0	0
Defined benefit plans net periodic pension cost	972,000	977,000	1,943,000	1,956,000
Defined benefit pension plan	565,000	2,049,000	1,048,000	2,638,000
International Plans
Defined benefit plans:
Service cost	900,000	862,000	1,808,000	1,926,000
Interest cost	10,762,000	11,062,000	21,545,000	22,441,000
Expected return on plan assets	(11,800,000)	(10,690,000)	(23,619,000)	(21,735,000)
Recognized prior service costs	94,000	96,000	184,000	194,000
Recognized loss	4,149,000	3,747,000	8,300,000	7,479,000
Amortization of transition liability			0	8,000
Settlement/curtailment gains	(289,000)	(366,000)	(289,000)	(2,061,000)
Defined benefit plans net periodic pension cost	3,816,000	4,711,000	7,929,000	8,252,000
Defined benefit pension plan	3,320,000	3,559,000	20,956,000	22,171,000
U. S. Plans
Defined benefit plans:
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year	1,700,000		1,700,000
International Plans
Defined benefit plans:
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year	$ 10,200,000		$ 10,200,000