CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	[1],[2]	$ 114,422	$ 162,279
Marketable securities	[1]	93,001	61,469
Total cash, cash equivalents, and marketable securities	[1]	207,423	223,748
Accounts receivable	[1]	180,872	222,735
Unbilled receivables	[1]	172,656	160,084
Other current assets	[1]	49,684	41,135
Total current assets	[1]	610,635	647,702
Long-term unbilled receivables	[1]	151,237	160,708
Goodwill	[1]	72,858	72,952
Other long-term assets	[1]	147,823	131,391
Total assets	[1]	982,553	1,012,753
Current liabilities:
Accounts payable	[1]	16,487	17,370
Accrued expenses	[1]	45,506	45,508
Accrued compensation and related expenses	[1]	84,671	66,040
Deferred revenue	[1]	185,145	165,850
Total current liabilities	[1]	331,809	294,768
Deferred income tax liabilities	[1]	6,939	38,463
Other long-term liabilities	[1]	22,274	23,652
Total liabilities	[1]	361,022	356,883
Commitments and Contingencies (Note 19)	[1]
Stockholders’ equity:
Preferred stock, $0.01 par value, 1,000 shares authorized; none issued	[1]	0	0
Common stock, $0.01 par value, 200,000 shares authorized; 78,526 and 78,081 shares issued and outstanding at December 31, 2018 and 2017, respectively	[1]	785	781
Additional paid-in capital	[1]	123,205	152,097
Retained earnings	[1]	510,863	509,697
Accumulated other comprehensive loss:
Net unrealized loss on available-for-sale marketable securities, net of tax	[1]	(249)	(232)
Foreign currency translation adjustments	[1]	(13,073)	(6,473)
Total stockholders’ equity	[1],[3]	621,531	655,870
Total liabilities and stockholders’ equity	[1]	$ 982,553	$ 1,012,753

[1] On January 1, 2018, the Company adopted the ASC 606 revenue recognition standard and adjusted prior periods to conform. See "Note 2. Significant Accounting Policies" for additional information.

[2] On January 1, 2018, the Company adopted the ASC 606 revenue recognition standard and adjusted prior periods to conform. See "Note 2. Significant Accounting Policies" for additional information.

[3] On January 1, 2018, the Company adopted the ASC 606 revenue recognition standard and adjusted prior periods to conform. See "Note 2. Significant Accounting Policies" for additional information.