Employee Benefit Plans - Actual and Target Allocations of Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 562,564	$ 552,817	$ 601,376
Defined Benefit Plan Fair Value Of Plan Assets Gross	$ 392,325	$ 386,049
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Actual plan asset allocations	100.00%	100.00%
Target plan asset allocations	100.00%
U.S. Pension Plan, Defined Benefit [Member] | Equity - Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 161,426	$ 157,796
U.S. Pension Plan, Defined Benefit [Member] | Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	43,272	39,159
U.S. Pension Plan, Defined Benefit [Member] | Private Placement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	11,200	6,751
U.S. Pension Plan, Defined Benefit [Member] | Collective trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 124,456	$ 124,128
U.S. Pension Plan, Defined Benefit [Member] | Equity securities [Member]
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Actual plan asset allocations	57.00%	57.00%
Target plan asset allocations	58.00%
U.S. Pension Plan, Defined Benefit [Member] | Fixed income investments [Member]
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Actual plan asset allocations	35.00%	33.00%
Target plan asset allocations	35.00%
U.S. Pension Plan, Defined Benefit [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 45,494	$ 42,391
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Actual plan asset allocations	8.00%	10.00%
Target plan asset allocations	7.00%
U.S. Pension Plan, Defined Benefit [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 289	$ 249
Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	148,514	159,436	163,510
Foreign Pension Plan [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25,037	23,113
Foreign Pension Plan [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,626	8,904
Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	104	829
Level 3 [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,999	8,904	$ 9,976
Level 3 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,999	8,904
Level 3 [Member] | Foreign Pension Plan [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 3 [Member] | Foreign Pension Plan [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,626	8,904
Level 3 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	221,799	251,132
Defined Benefit Plan Fair Value Of Plan Assets Gross	221,799	251,132
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Equity - Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	161,426	157,796
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	43,272	39,159
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Private Placement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	11,200	6,751
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Collective trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 1 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 1 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25,141	23,942
Level 1 [Member] | Foreign Pension Plan [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25,037	23,113
Level 1 [Member] | Foreign Pension Plan [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 1 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	104	829
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	170,526	134,917
Defined Benefit Plan Fair Value Of Plan Assets Gross	170,526	134,917
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Equity - Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Private Placement [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Collective trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | U.S. Pension Plan, Defined Benefit [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	104,374	126,590
Level 2 [Member] | Foreign Pension Plan [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | Foreign Pension Plan [Member] | Real estate funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Level 2 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 0	$ 0