Summary of Significant Accounting Policies - Impact of Adoption of ASU2016-02 (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 10, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 152,178	$ 495,000
Total assets	31,771,440				$ 30,587,012
Other accrued expenses	777,865				802,388
Operating lease liabilities	92,796
Long-term deferred revenue and other long-term liabilities	636,718				470,932
Total liabilities	21,074,207				21,532,755
Total stockholders' equity (deficit)	10,169,028		$ 9,330,511	$ 8,951,217	8,594,189	$ 8,243,038	$ 7,806,127	$ 7,325,263	$ 6,937,906
Total liabilities and stockholders' equity (deficit)	31,771,440				$ 30,587,012
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	152,178
Total assets	31,771,440
Other accrued expenses	777,865
Operating lease liabilities	92,796
Long-term deferred revenue and other long-term liabilities	636,718
Total liabilities	21,074,207
Total stockholders' equity (deficit)	10,169,028
Total liabilities and stockholders' equity (deficit)	31,771,440
Accounting Standards Update 2016-02 [Member] | As would have been reported under previous standards
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total assets	31,619,262
Other accrued expenses	720,128
Long-term deferred revenue and other long-term liabilities	635,073
Total liabilities	20,922,029
Total stockholders' equity (deficit)	10,169,028
Total liabilities and stockholders' equity (deficit)	31,619,262
Accounting Standards Update 2016-02 [Member] | Impact of adopting ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	152,178
Total assets	152,178
Other accrued expenses	57,737
Operating lease liabilities	92,796
Long-term deferred revenue and other long-term liabilities	1,645
Total liabilities	152,178
Total liabilities and stockholders' equity (deficit)	$ 152,178