Pension and Postretirement Benefits - Fair value of the domestic plans' assets by asset class (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	$ 10,872	$ 10,624
Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	10,655	10,401
Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	217	223
Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
US Postretirement Benefit Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	520
US Postretirement Benefit Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	520
US Postretirement Benefit Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
US Postretirement Benefit Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
Foreign Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	11,560	12,997
Foreign Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	11,165	12,620
Foreign Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	395	377
Foreign Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Aggregate fixed income securities | Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	5,966
Aggregate fixed income securities | Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	5,966
Aggregate fixed income securities | Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
Aggregate fixed income securities | Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
Aggregate fixed income securities | US Postretirement Benefit Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	407
Aggregate fixed income securities | US Postretirement Benefit Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	407
Aggregate fixed income securities | US Postretirement Benefit Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
Aggregate fixed income securities | US Postretirement Benefit Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
U.S. equity securities | Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	4,542
U.S. equity securities | Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	4,542
U.S. equity securities | Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
U.S. equity securities | Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
U.S. equity securities | US Postretirement Benefit Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	109
U.S. equity securities | US Postretirement Benefit Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	109
U.S. equity securities | US Postretirement Benefit Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
U.S. equity securities | US Postretirement Benefit Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0
U.S. equity securities | Foreign Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	1,269	1,185
U.S. equity securities | Foreign Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	1,269	1,185
U.S. equity securities | Foreign Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
U.S. equity securities | Foreign Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Cash | Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	147	10,401
Cash | Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	147	10,401
Cash | Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Cash | Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Cash | US Postretirement Benefit Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	4	1,397
Cash | US Postretirement Benefit Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	4	1,397
Cash | US Postretirement Benefit Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Cash | US Postretirement Benefit Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Equity Securities | Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	217	223
Equity Securities | Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Equity Securities | Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	217	223
Equity Securities | Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Equity Securities | Foreign Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	336	197
Equity Securities | Foreign Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	336	197
Equity Securities | Foreign Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Equity Securities | Foreign Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Canadian Fixed Income Securities | Foreign Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	5,174	6,744
Canadian Fixed Income Securities | Foreign Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	5,174	6,744
Canadian Fixed Income Securities | Foreign Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
Canadian Fixed Income Securities | Foreign Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	0	0
International equity securities | Foreign Pension Plans
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	4,781	4,871
International equity securities | Foreign Pension Plans | Quoted Prices in Active Markets (Level 1)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	4,386	4,494
International equity securities | Foreign Pension Plans | Significant Other Observable Inputs (Level 2)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	395	377
International equity securities | Foreign Pension Plans | Significant Unobserved Inputs (Level 3)
Fair value of the domestic plans assets by asset class
Fair value measurement domestic pension plans	$ 0	$ 0