CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 790.6	$ 669.2
Marketable investments	814.5	746.7
Accounts receivable, no allowance for 2019 and 2018	159.8	175.7
Inventories, net	96.2	101.0
Other current assets	81.4	75.4
Total current assets	1,942.5	1,768.0
Marketable investments	411.3	442.6
Goodwill and other intangible assets, net	170.8	170.8
Property, plant and equipment, net	701.2	699.7
Deferred tax assets, net	265.5	95.7
Other non-current assets	235.4	224.2
Total assets	3,726.7	3,401.0
Current liabilities:
Accounts payable and accrued expenses	139.4	166.1
Share tracking awards plan	77.5	72.2
Other current liabilities	53.1	38.3
Total current liabilities	270.0	276.6
Line of credit	1,050.0	250.0
Other non-current liabilities	68.5	66.6
Total liabilities	1,388.5	593.2
Commitments and contingencies
Temporary equity	19.2	19.2
Stockholders' equity:
Common stock, par value $.01, 245,000,000 shares authorized, 70,424,937 and 70,207,581 shares issued, and 43,805,721 and 43,588,365 shares outstanding at March 31, 2019 and December 31, 2018, respectively	0.7	0.7
Additional paid-in capital	1,967.6	1,940.2
Accumulated other comprehensive loss	(5.2)	(7.9)
Treasury stock, 26,619,216 shares at March 31, 2019 and December 31, 2018	(2,579.2)	(2,579.2)
Retained earnings	2,935.1	3,434.8
Total stockholders' equity	2,319.0	2,788.6
Total liabilities and stockholders' equity	3,726.7	3,401.0
Preferred stock
Stockholders' equity:
Preferred stock, par value $.01, 10,000,000 shares authorized, no shares issued
Series A junior participating preferred stock
Stockholders' equity:
Preferred stock, par value $.01, 10,000,000 shares authorized, no shares issued