Pension Plans and Other Postretirement Benefits Components of Pension and Postretirement Benefits Expense (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss (gain)	$ (38,900)	$ 112,600	$ 2,800	$ 15,400
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost					$ 1,233	$ 7,029	$ 12,177
Interest cost					31,231	30,491	28,406
Expected return on assets					(41,635)	(39,714)	(38,975)
Actuarial loss (gain)					2,577	116,705	(130,297)
Amortization of prior service benefit					75	(727)	(741)
Total net pension benefits (credit) cost					$ (6,519)	$ 113,784	$ (129,430)
Weighted-average assumption percentages:
Discount rate					4.18%	5.14%	4.10%
Expected return on plan assets					6.85%	6.91%	7.25%
Rate of compensation increase					0.00%	3.50%	3.50%
Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost					$ 6,034	$ 1,746	$ 1,785
Interest cost					9,875	1,571	1,477
Expected return on assets					(6,507)	(427)	(417)
Actuarial loss (gain)					(35,813)	10,270	(2,619)
Amortization of prior service benefit					43	50	52
Total net pension benefits (credit) cost					$ (26,368)	$ 13,210	$ 278
Weighted-average assumption percentages:
Discount rate					2.34%	3.41%	3.12%
Expected return on plan assets					5.63%	4.00%	4.35%
Rate of compensation increase					3.16%	3.16%	3.36%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost					$ 137	$ 216	$ 309
Interest cost					2,573	3,040	2,764
Expected return on assets					(244)	(342)	(413)
Actuarial loss (gain)					(5,707)	3,868	(6,120)
Amortization of prior service benefit					(95)	(95)	(95)
Settlements/curtailments					(2,594)	0	0
Total net pension benefits (credit) cost					$ (5,930)	$ 6,687	$ (3,555)
Weighted-average assumption percentages:
Discount rate					4.15%	5.03%	4.00%
Expected return on plan assets					7.00%	7.00%	7.00%
Rate of compensation increase					3.50%	3.50%	3.50%