UNAUDITED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total		Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2017	$ 11,260,598		$ 487	$ (8,698,829)	$ 5,783,089	$ 13,938,869	$ 236,982
Balance (in shares) at Dec. 31, 2017			62,689,000	(14,217,000)
Increase (Decrease) in Stockholders' Equity
Net income	1,584,582
Foreign currency translation adjustments, net of tax charge of $20,358	(66,986)	[1]					(66,986)
Net unrealized losses on marketable securities, net of tax benefit of $998	(5,191)	[2]					(5,191)
Reclassification adjustment for convertible debt in mezzanine	(42,680)				(42,680)
Exercise of stock options and vesting of restricted stock units and/or performance share units	1,329		$ 2		1,327
Exercise of stock options and vesting of restricted stock units and/or performance share units (in shares)			186,000
Repurchase of common stock	$ (1,931,532)			$ (1,931,532)
Repurchase of common stock (in shares)	(945,693)			(946,000)
Stock-based compensation and other stock-based payments	$ 146,682				146,682
Conversion of debt	(773,150)				(773,150)
Common stock issued in an acquisition	110,441
Common stock issued in an acquisition (in shares)			52,000
Balance (in shares) at Jun. 30, 2018			62,927,000	(15,163,000)
Balance at Jun. 30, 2018	10,472,632		$ 489	$ (10,630,361)	$ 5,225,709	15,953,078	(76,283)
Increase (Decrease) in Stockholders' Equity
Cumulative effect of adoption of accounting standard updates	$ 188,539					$ 429,627	$ (241,088)

[1] (1) Foreign currency translation adjustments result from currency fluctuations on the translation of the Company's international non-U.S. Dollar denominated net assets. Foreign currency translation adjustments were unfavorable for the three and six months ended June 30, 2018 compared to the three and six months ended June 30, 2017 because the U.S. Dollar strengthened against certain currencies in which the Company's net assets are denominated. During the three and six months ended June 30, 2018, the Company recorded deferred tax benefits of $21.0 million and $10.5 million, respectively, related to foreign currency translation adjustments to its one-time deemed repatriation tax liability recorded at December 31, 2017 and current year foreign earnings subject to U.S. federal and state income tax, resulting from the introduction of the U.S. Tax Cuts and Jobs Act (the "Tax Act"). Prior to January 1, 2018, foreign currency translation adjustments excluded U.S. federal and state income taxes as a result of the Company's intention to indefinitely reinvest the earnings of its international subsidiaries outside of the United States. Foreign currency translation adjustments also include tax charges of $57.3 million and $30.8 million for the three and six months ended June 30, 2018, respectively, and tax benefits of $100.6 million and $120.3 million for the three and six months ended June 30, 2017, respectively, associated with the Company's Euro-denominated debt, which is designated as a net investment hedge against the impact of currency fluctuations of the Company's Euro-denominated net assets (see Note 8).

[2] (3) Net unrealized (losses) gains on marketable securities for the three and six months ended June 30, 2018 include net unrealized losses of $4.3 million and $6.1 million before tax, respectively, of which net unrealized losses of $15.6 million and net unrealized gains of $16.8 million, respectively, were exempt from tax in the Netherlands. Net unrealized gains of $11.3 million and net unrealized losses of $22.9 million for the three and six months ended June 30, 2018, respectively, were taxable at a 25% tax rate in the Netherlands, resulting in a tax charge of $2.8 million and a tax benefit of $5.7 million, respectively. The Company also recorded a U.S. tax benefit of $2.4 million and a U.S. tax charge of $4.7 million for the three and six months ended June 30, 2018, respectively, related to these investments. Net unrealized (losses) gains on marketable securities for the three and six months ended June 30, 2017 include net unrealized gains of $195.0 million and $548.8 million before tax, respectively, of which net unrealized gains of $161.4 million and $485.1 million, respectively, were exempt from tax in the Netherlands. Net unrealized gains of $33.6 million and $63.7 million for the three and six months ended June 30, 2017, respectively, were taxable at a 25% tax rate in the Netherlands, resulting in tax charges of $8.0 million and $15.9 million, respectively.