Stock Repurchases and Dividends	12 Months Ended
Dec. 31, 2018
Equity [Abstract]
Stock Repurchases and Dividends	11. STOCK REPURCHASES AND DIVIDENDS SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire its Securities, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the years ended December 31, 2018, 2017 and 2016, the Company acquired no shares of Common Stock for treasury under the Securities repurchase plan. As of December 31, 2018, SEACOR had remaining authorization for Securities repurchases of $66.7 million. During the years ended December 31, 2017 and 2016, the Company acquired for treasury 212,659 and 47,455 shares of Common Stock, respectively, for aggregate purchase prices of $12.3 million and $2.4 million, respectively, from its employees to cover their tax withholding obligations related to share award transactions. These shares were purchased in accordance with the terms of the Company’s Share Incentive Plans and not pursuant to the repurchase authorizations granted by SEACOR’s Board of Directors. On June 1, 2017, the Company completed the Spin-off of SEACOR Marine by means of a dividend of all of the issued and outstanding common stock of SEACOR Marine to SEACOR’s shareholders. In the Spin-off, holders of SEACOR Common Stock received approximately 1.005 shares of SEACOR Marine common stock for each share of SEACOR Common Stock held as of the record date for the Spin-off. On December 20, 2017, the Company distributed 3,977,135 shares of Dorian common stock with a value of $31.4 million (based on the closing share price on that date) to its stockholders with each holder of Common Stock receiving approximately 0.2215 shares of Dorian common stock for each share of SEACOR Common Stock held as of the record date for such distribution. The Compensation Committee of the Board of Directors elected, at its discretion, to distribute shares of Dorian on the Company’s restricted shares outstanding on the record date rather than depositing the shares in escrow pending the lapsing of restrictions.

11. STOCK REPURCHASES AND DIVIDENDS

SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire its Securities, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions.

During the years ended December 31, 2018, 2017 and 2016, the Company acquired no shares of Common Stock for treasury under the Securities repurchase plan. As of December 31, 2018, SEACOR had remaining authorization for Securities repurchases of $66.7 million.

During the years ended December 31, 2017 and 2016, the Company acquired for treasury 212,659 and 47,455 shares of Common Stock, respectively, for aggregate purchase prices of $12.3 million and $2.4 million, respectively, from its employees to cover their tax withholding obligations related to share award transactions. These shares were purchased in accordance with the terms of the Company’s Share Incentive Plans and not pursuant to the repurchase authorizations granted by SEACOR’s Board of Directors.

On June 1, 2017, the Company completed the Spin-off of SEACOR Marine by means of a dividend of all of the issued and outstanding common stock of SEACOR Marine to SEACOR’s shareholders. In the Spin-off, holders of SEACOR Common Stock received approximately 1.005 shares of SEACOR Marine common stock for each share of SEACOR Common Stock held as of the record date for the Spin-off.

On December 20, 2017, the Company distributed 3,977,135 shares of Dorian common stock with a value of $31.4 million (based on the closing share price on that date) to its stockholders with each holder of Common Stock receiving approximately 0.2215 shares of Dorian common stock for each share of SEACOR Common Stock held as of the record date for such distribution. The Compensation Committee of the Board of Directors elected, at its discretion, to distribute shares of Dorian on the Company’s restricted shares outstanding on the record date rather than depositing the shares in escrow pending the lapsing of restrictions.