Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 239,246	$ 256,638
Restricted cash	2,982	2,249
Marketable securities	42,761	76,137
Receivables:
Trade, net of allowance for doubtful accounts of $2,390 and $2,989 in 2017 and 2016, respectively	110,465	108,641
Other	33,870	35,482
Inventories	4,377	2,582
Prepaid expenses and other	6,594	3,707
Discontinued operations	0	277,365
Total current assets	440,295	762,801
Property and Equipment:
Historical cost	1,351,741	1,178,556
Accumulated depreciation	502,544	444,559
Property, Plant and Equipment, Net In Service	849,197	733,997
Construction in progress	28,728	246,010
Net property and equipment	877,925	980,007
Investments, at Equity, and Advances to 50% or Less Owned Companies	173,441	175,461
Construction Reserve Funds	51,339	75,753
Goodwill	32,761	32,758
Intangible Assets, Net	28,106	20,078
Other Assets	9,469	17,189
Discontinued Operations	0	798,274
Total Assets	1,613,336	2,862,321
Current Liabilities:
Current portion of long-term debt	77,842	163,202
Accounts payable and accrued expenses	44,013	59,563
Accrued wages and benefits	14,624	12,398
Accrued interest	4,209	5,036
Accrued income taxes	0	3,059
Short sales of marketable securities	0	1,274
Accrued capital, repair and maintenance expenditures	2,172	15,092
Other current liabilities	36,325	25,305
Discontinued operations	0	85,020
Total current liabilities	179,185	369,949
Long-Term Debt	501,505	631,084
Exchange Option Liability on Subsidiary Convertible Senior Notes	0	19,436
Deferred Income Taxes		157,441
Deferred Income Tax Liabilities, Net	101,422
Deferred Gains and Other Liabilities	77,863	98,098
Discontinued Operations	0	390,045
Total liabilities	859,975	1,666,053
SEACOR Holdings Inc. stockholders’ equity:
Preferred stock, $.01 par value, 10,000,000 shares authorized; none issued nor outstanding	0	0
Common stock, $.01 par value, 60,000,000 shares authorized; 38,656,505 and 37,939,032 shares issued in 2017 and 2016, respectively	387	379
Additional paid-in capital	1,573,013	1,518,635
Retained earnings	419,128	910,723
Shares held in treasury of 20,716,878 and 20,538,327 in 2017 and 2016, respectively, at cost	1,368,300	1,357,331
Accumulated other comprehensive loss, net of tax	(545)	(11,514)
Stockholders' equity attributable to SEACOR Holdings Inc.	623,683	1,060,892
Noncontrolling interests in subsidiaries	129,678	135,376
Total equity	753,361	1,196,268
Liabilities and stockholders' equity, total	$ 1,613,336	$ 2,862,321

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.