Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Accounts receivable, including affiliate balances | $ 0.8 | $ 0.6 |
| Accumulated depreciation on vessels and equipment | 459.3 | 391.0 |
| Accounts payable, including affiliate balances | $ 1.1 | $ 1.4 |
| Common stock, shares authorized (in shares) | 300,000,000 | 300,000,000 |
| Class A [Member] | ||
| Common stock, shares authorized (in shares) | 200,000,000 | 200,000,000 |
| Common stock, shares issued (in shares) | 136,100,000 | 132,800,000 |
| Common stock, shares outstanding (in shares) | 136,100,000 | 132,800,000 |
| Class B [Member] | ||
| Common stock, shares authorized (in shares) | 100,000,000 | 100,000,000 |
| Common stock, shares issued (in shares) | 23,200,000 | 23,200,000 |
| Common stock, shares outstanding (in shares) | 23,200,000 | 23,200,000 |
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- Definition Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition For an unclassified balance sheet, amount of receivables arising from transactions with related parties. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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