Pension and Other Postretirement Benefits - Fair Value Hierarchy - Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 119,309	$ 106,900
Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	49,252	44,622
Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12,448	10,744
Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	57,609	51,534	47,160
Insurance Contract [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	57,175	51,146	46,797
Real Estate Fund [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	434	388	363
Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	50,650	45,991	43,470
Domestic [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	50,650	45,991
Domestic [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	49,247	44,526
Domestic [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,403	1,465
Domestic [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Cash and Cash Equivalents [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	825	905
Domestic [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	825	905
Domestic [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Securities Large Cap [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	14,801	12,195
Domestic [Member] | Equity Securities Large Cap [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	14,801	12,195
Domestic [Member] | Equity Securities Large Cap [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Securities Large Cap [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Funds Large Cap [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,820	6,551
Domestic [Member] | Equity Funds Large Cap [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,820	6,551
Domestic [Member] | Equity Funds Large Cap [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Funds Large Cap [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Securities Small Cap [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	771	539
Domestic [Member] | Equity Securities Small Cap [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	771	539
Domestic [Member] | Equity Securities Small Cap [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Securities Small Cap [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Funds Small Cap [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,384	1,910
Domestic [Member] | Equity Funds Small Cap [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,384	1,910
Domestic [Member] | Equity Funds Small Cap [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Funds Small Cap [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Funds International Developed And Emerging Markets [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,895	3,107
Domestic [Member] | Equity Funds International Developed And Emerging Markets [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,895	3,107
Domestic [Member] | Equity Funds International Developed And Emerging Markets [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Funds International Developed And Emerging Markets [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Securities International Developed And Emerging Markets [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,929	2,527
Domestic [Member] | Equity Securities International Developed And Emerging Markets [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,929	2,527
Domestic [Member] | Equity Securities International Developed And Emerging Markets [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Equity Securities International Developed And Emerging Markets [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Corporate Debt Securities [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,144	10,297
Domestic [Member] | Corporate Debt Securities [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,144	10,297
Domestic [Member] | Corporate Debt Securities [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Corporate Debt Securities [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Fixed Income Funds [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,486	6,483
Domestic [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,486	6,483
Domestic [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Domestic And Foreign Government Debt Securities [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	192	12
Domestic [Member] | Domestic And Foreign Government Debt Securities [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	192	12
Domestic [Member] | Domestic And Foreign Government Debt Securities [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Domestic And Foreign Government Debt Securities [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Pooled Separate Accounts [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,403	1,465
Domestic [Member] | Pooled Separate Accounts [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Domestic [Member] | Pooled Separate Accounts [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,403	1,465
Domestic [Member] | Pooled Separate Accounts [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	68,659	60,909	54,968
Foreign [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	68,659	60,909
Foreign [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5	96
Foreign [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	11,045	9,279
Foreign [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	57,609	51,534
Foreign [Member] | Cash and Cash Equivalents [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5	96
Foreign [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5	96
Foreign [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Fixed Income Funds [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,448	4,207
Foreign [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,448	4,207
Foreign [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Insurance Contract [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	57,175	51,146
Foreign [Member] | Insurance Contract [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Insurance Contract [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Insurance Contract [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	57,175	51,146
Foreign [Member] | Equity Funds Diversified [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,597	5,072
Foreign [Member] | Equity Funds Diversified [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Equity Funds Diversified [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,597	5,072
Foreign [Member] | Equity Funds Diversified [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Real Estate Fund [Member] | Total Defined Benefit Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	434	388
Foreign [Member] | Real Estate Fund [Member] | Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Real Estate Fund [Member] | Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Foreign [Member] | Real Estate Fund [Member] | Fair Value Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 434	$ 388