Pension and Postretirement Benefits - Fair value of the plans' assets by asset class (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	$ 10,479	$ 11,198
Pension Plans | Aggregate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	5,453	6,534
Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	4,459	3,855
Pension Plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	357	552
Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	210	257
Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	9,705	11,747
Foreign Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	1,012	1,236
Foreign Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	425	451
Foreign Pension Plans | Canadian Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	4,372	5,367
Foreign Pension Plans | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	3,896	4,693
Quoted Prices in Active Markets (Level 1) | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	10,269	10,941
Quoted Prices in Active Markets (Level 1) | Pension Plans | Aggregate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	5,453	6,534
Quoted Prices in Active Markets (Level 1) | Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	4,459	3,855
Quoted Prices in Active Markets (Level 1) | Pension Plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	357	552
Quoted Prices in Active Markets (Level 1) | Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	9,330	11,327
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	1,012	1,236
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	425	451
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | Canadian Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	4,372	5,367
Quoted Prices in Active Markets (Level 1) | Foreign Pension Plans | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	3,521	4,273
Significant Other Observable Inputs (Level 2) | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	210	257
Significant Other Observable Inputs (Level 2) | Pension Plans | Aggregate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Other Observable Inputs (Level 2) | Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Other Observable Inputs (Level 2) | Pension Plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Other Observable Inputs (Level 2) | Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	210	257
Significant Other Observable Inputs (Level 2) | Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	375	420
Significant Other Observable Inputs (Level 2) | Foreign Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Other Observable Inputs (Level 2) | Foreign Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Other Observable Inputs (Level 2) | Foreign Pension Plans | Canadian Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Other Observable Inputs (Level 2) | Foreign Pension Plans | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	375	420
Significant Unobserved Inputs (Level 3) | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Pension Plans | Aggregate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Pension Plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Foreign Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Foreign Pension Plans | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Foreign Pension Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	0
Significant Unobserved Inputs (Level 3) | Foreign Pension Plans | Canadian Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	0	$ 0
Significant Unobserved Inputs (Level 3) | Foreign Pension Plans | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurement domestic pension plans	$ 0