Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Increase in net cash provided by operating activities	[1]	$ 631,627	$ 174,295	$ 237,784
Decrease in net cash provided by financing activities	[1]	$ (51,469)	(32,745)	(25,854)
Accounting Standards Update 2016-09
Increase in net cash provided by operating activities			42,900	37,300
Decrease in net cash provided by financing activities			$ 42,900	$ 37,300

[1] During our first fiscal quarter of 2017, we adopted Accounting Standards Update 2016-09, "Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting." Refer to Note 1- Recently Adopted Accounting Pronouncements for further details. This adoption resulted in an increase in net cash provided by operating activities and a corresponding decrease in net cash provided by financing activities of $42.9 million and $37.3 million for the years ended December 31, 2016 and 2015, respectively.