The selected consolidated financial data presented below is derived from the Consolidated Financial Statements and related Notes of the Company, and should be read in connection with those statements, some of which are included herein. Selected financial data reflects results of any acquired business from the date of acquisition, including data related to KAYAK from its acquisition date of May 21, 2013, OpenTable from its acquisition date of July 24, 2014 and the Momondo Group (which is managed as part of the Company's KAYAK business) from its acquisition date of July 24, 2017. The information set forth below is not necessarily indicative of future results and should be read in conjunction with Part II Item 7 Management's Discussion and Analysis of Financial Condition and Results of Operations.
Year Ended December 31,
2017
2016
2015
2014
2013
(In thousands, except per share amounts)
Total revenues
$
12,681,082
$
10,743,006
$
9,223,987
$
8,441,971
$
6,793,306
Cost of revenues
250,537
428,314
632,180
857,841
1,077,420
Gross profit
12,430,545
10,314,692
8,591,807
7,584,130
5,715,886
Total operating expenses(1)
7,892,553
7,408,379
5,332,900
4,510,818
3,303,472
Operating income(1)
4,537,992
2,906,313
3,258,907
3,073,312
2,412,414
Total other expense
139,670
193,075
130,587
83,864
115,877
Income tax expense(2)
2,057,557
578,251
576,960
567,695
403,739
Net income(1) (2)
2,340,765
2,134,987
2,551,360
2,421,753
1,892,798
Net income attributable to noncontrolling interests(3)
—
—
—
—
135
Net income applicable to common stockholders(1) (2)
2,340,765
2,134,987
2,551,360
2,421,753
1,892,663
Net income applicable to common stockholders per basic common share (1) (2)
47.78
43.14
50.09
46.30
37.17
Net income applicable to common stockholders per diluted common share (1) (2)
46.86
42.65
49.45
45.67
36.11
Total assets
25,451,263
19,838,973
17,420,575
14,770,977
10,428,543
Long-term obligations(4)
11,403,707
8,127,895
7,185,796
4,862,730
2,289,039
Total liabilities
14,187,702
9,990,293
8,625,106
6,203,954
3,510,281
Total stockholders' equity
11,260,598
9,820,142
8,795,469
8,566,694
6,909,729
(1)
Includes a non-cash charge related to an impairment of OpenTable goodwill of $940.7 million, which is not tax deductible, for the year ended December 31, 2016 (see Note 9 to the Consolidated Financial Statements). The goodwill impairment charge reduced the 2016 basic and diluted net income per share by $19.01 and $18.79, respectively.
(2)
Includes a provisional tax expense of $1.6 billion related to a one-time transition tax on the mandatory deemed repatriation of accumulated unremitted international earnings and a provisional net tax benefit of approximately $217 million related to the remeasurement of the Company’s U.S. deferred tax assets and liabilities, for the year ended December 31, 2017, as a result of the U.S. Tax Cuts and Jobs Act enacted on December 22, 2017 (see Note 13 to the Consolidated Financial Statements), which reduced the 2017 basic and diluted net income per share by $27.47 and $26.94, respectively.
(3)
Redeemable noncontrolling interests relates to the Company's purchase of Rentalcars.com in May 2010. In April 2013, the Company purchased the remaining outstanding shares underlying the redeemable noncontrolling interests in connection with the exercise of certain call and put options in March 2013.
(4)
Includes convertible debt which is classified as a current liability, where applicable.