Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

The Company's cash and cash equivalents balances comprise the following:



	December 31, 2017			December 31, 2016
(in thousands, except percentages)	Amount		% of Total	Amount		% of Total
Cash accounts	$	568,587	64.5	$	488,504	59.4
Money market funds	312,914		35.5	333,975		40.6
Total	$	881,501		$	822,479

The details of basic and diluted EPS are as follows:



	Year Ended December 31,
(in thousands, except per share data)	2017		2016		2015
Net income	$	259,251	$	265,636	$	252,521
Weighted average shares outstanding – basic	84,988		87,227		89,561
Dilutive effect of stock plans	1,866		1,742		1,941
Weighted average shares outstanding – diluted	86,854		88,969		91,502
Basic earnings per share	$	3.05	$	3.05	$	2.82
Diluted earnings per share	$	2.98	$	2.99	$	2.76
Anti-dilutive shares	84		260		206

The following table outlines concentrations of risk with respect to the Company's revenue:



	Year Ended December 31,
(as a % of revenue)	2017		2016		2015
Revenue from channel partners	25	%	24	%	24	%
Largest channel partner	5	%	5	%	5	%
2^nd largest channel partner	2	%	2	%	2	%

The following table outlines concentrations of risk with respect to the Company's cash and cash equivalents:



	As of December 31,
(in thousands)	2017		2016
Cash and cash equivalents held domestically	$	561,417	$	593,348
Cash and cash equivalents held by foreign subsidiaries	320,084		229,131
Cash and cash equivalents held in excess of deposit insurance, foreign and domestic	852,138		805,374
Largest balance of cash and cash equivalents held with one financial institution, foreign and domestic	328,902		377,602