Pension and Other Postretirement Benefits - Fair Value Hierarchy - Assets (Details) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
In Thousands, unless otherwise specified |
Total Defined Benefit Plan Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | $136,212 | $119,309 | |
Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 38,082 | 38,916 | |
Fair Value Inputs Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 25,235 | 22,784 | |
Fair Value Inputs Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 72,895 | 57,609 | 51,534 |
Insurance Contract [Member] | Fair Value Inputs Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 72,417 | 57,175 | 51,146 |
Real Estate Fund [Member] | Fair Value Inputs Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 478 | 434 | 388 |
Domestic [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 49,689 | 50,650 | 45,991 |
Domestic [Member] | Total Defined Benefit Plan Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 49,689 | 50,650 | |
Domestic [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 38,006 | 38,911 | |
Domestic [Member] | Fair Value Inputs Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 11,683 | 11,739 | |
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 | 490 | 825 | |
Domestic [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 490 | 825 | |
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 | 14,956 | 14,801 | |
Domestic [Member] | Equity Securities Large Cap [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 14,956 | 14,801 | |
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 | 6,339 | 6,820 | |
Domestic [Member] | Equity Funds Large Cap [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 6,339 | 6,820 | |
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 | 920 | 771 | |
Domestic [Member] | Equity Securities Small Cap [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 920 | 771 | |
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 | 2,416 | 2,384 | |
Domestic [Member] | Equity Funds Small Cap [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 2,416 | 2,384 | |
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 | 5,638 | 5,895 | |
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 | 5,638 | 5,895 | |
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 | 2,600 | 2,929 | |
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 | 2,600 | 2,929 | |
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 | 9,848 | 10,144 | |
Domestic [Member] | Corporate Debt Securities [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 0 | 0 | |
Domestic [Member] | Corporate Debt Securities [Member] | Fair Value Inputs Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 9,848 | 10,144 | |
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 | 4,647 | 4,486 | |
Domestic [Member] | Fixed Income Funds [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 4,647 | 4,486 | |
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 | 406 | 192 | |
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 | 0 | 0 | |
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 | 406 | 192 | |
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 | 1,429 | 1,403 | |
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 | 1,429 | 1,403 | |
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 | 86,523 | 68,659 | 60,909 |
Foreign [Member] | Total Defined Benefit Plan Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 86,523 | 68,659 | |
Foreign [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 76 | 5 | |
Foreign [Member] | Fair Value Inputs Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 13,552 | 11,045 | |
Foreign [Member] | Fair Value Inputs Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 72,895 | 57,609 | |
Foreign [Member] | Cash and Cash Equivalents [Member] | Total Defined Benefit Plan Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 76 | 5 | |
Foreign [Member] | Cash and Cash Equivalents [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 76 | 5 | |
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 | 4,946 | 4,448 | |
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 | 4,946 | 4,448 | |
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 | 72,417 | 57,175 | |
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 | 72,417 | 57,175 | |
Foreign [Member] | Equity Funds Diversified [Member] | Total Defined Benefit Plan Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 6,565 | 6,597 | |
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 | 6,565 | 6,597 | |
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 | 478 | 434 | |
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 | 478 | 434 | |
Foreign [Member] | Commingled Funds [Member] | Total Defined Benefit Plan Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 2,041 | | |
Foreign [Member] | Commingled Funds [Member] | Fair Value Inputs Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 0 | | |
Foreign [Member] | Commingled Funds [Member] | Fair Value Inputs Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | 2,041 | | |
Foreign [Member] | Commingled Funds [Member] | Fair Value Inputs Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Fair Value of Plan Assets | $0 | | |