Pension Plan and Postretirement Benefits Other Than Pension (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Pension Plan and Postretirement Benefits Other than Pension
Amount of transfer between levels	$ 0	$ 0
Level 3
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	4,019	1,772
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at beginning of year	1,772	0
Purchases, issuances and settlements	1,900	1,772
Valuation change	347
Fair value of plan assets at end of year	4,019	1,772
Pension Benefits
Pension Plan and Postretirement Benefits Other than Pension
Amount of transfer between levels	0	0
Total fair value	170,430	133,911	106,568
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at beginning of year	133,911	103,404	106,568
Fair value of plan assets at end of year	170,430	133,911	106,568
Pension Benefits | Equity securities: Domestic
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	54,558	51,289
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	54,558	51,289
Pension Benefits | Equity securities: Foreign
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	67,889	53,291
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	67,889	53,291
Pension Benefits | Equity derivatives
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	471
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	471
Pension Benefits | Fixed income securities: Mortgage-backed securities
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	17	50
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	17	50
Pension Benefits | Fixed income securities: Corporate bond
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	1,900
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	1,900
Pension Benefits | Private equity
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	2,119	1,772
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	2,119	1,772
Pension Benefits | Gold bullion
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	12,316	13,452
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	12,316	13,452
Pension Benefits | Total investment securities
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	139,270	119,854
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	139,270	119,854
Pension Benefits | Cash and other
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	31,160	14,057
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	31,160	14,057
Pension Benefits | Level 1 | Equity securities: Domestic
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	54,558	51,289
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	54,558	51,289
Pension Benefits | Level 1 | Equity securities: Foreign
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	67,889	53,291
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	67,889	53,291
Pension Benefits | Level 1 | Gold bullion
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	12,316	13,452
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	12,316	13,452
Pension Benefits | Level 1 | Total investment securities
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	134,763	118,032
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	134,763	118,032
Pension Benefits | Level 2 | Equity derivatives
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	471
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	471
Pension Benefits | Level 2 | Fixed income securities: Mortgage-backed securities
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	17	50
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	17	50
Pension Benefits | Level 2 | Total investment securities
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	488	50
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	488	50
Pension Benefits | Level 3 | Fixed income securities: Corporate bond
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	1,900
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	1,900
Pension Benefits | Level 3 | Private equity
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	2,119	1,772
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	2,119	1,772
Pension Benefits | Level 3 | Total investment securities
Pension Plan and Postretirement Benefits Other than Pension
Total fair value	4,019	1,772
Summary of the activity of plan assets categorized as Level 3 during the period
Fair value of plan assets at end of year	$ 4,019	$ 1,772