Income taxes (Tables)

12 Months Ended

Sep. 30, 2019

Income Tax Disclosure [Abstract]

Components of income from continuing operations before income taxes

The components of income before income taxes and the corresponding provision for income taxes are as follows (in thousands):

	Year ended September 30,
	2019		2018		2017
Income before income taxes:
United States	$	280,092	$	248,360	$	257,910
Foreign	37,228		50,849		56,325
Income before income taxes	$	317,320	$	299,209	$	314,235

Provision for income taxes

	Year ended September 30,
	2019		2018		2017
Current provision:
Federal	$	37,123	$	42,318	$	70,476
State and local	14,480		13,459		15,594
Foreign	12,561		15,895		11,221
Total current provision	64,164		71,672		97,291
Deferred tax expense (benefit):
Federal	12,627		4,106		5,490
State and local	3,013		2,902		643
Foreign	(2,979)		(287)		(1,371)
Total deferred tax expense (benefit)	12,661		6,721		4,762
Provision for income taxes	$	76,825	$	78,393	$	102,053

Reconciliation of tax provision using the federal statutory income tax rate to reported provision

The provision for income taxes differs from that which would have resulted from the use of this rate is as follows (in thousands):

	Year ended September 30,
	2019		2018		2017
Federal income tax provision at statutory rate of 21%, 24.5% and 35%, respectively	$	66,637	$	73,396	$	109,982
State income taxes, net of federal benefit	14,825		12,348		10,554
Foreign taxation	1,210		(1,531)		(6,940)
Permanent items	2,682		1,176		970
Tax credits	(3,730)		(2,438)		(4,851)
Toll tax	(481)		9,425		—
Deferred tax liability - tax rate change	—		(10,514)		—
Vesting of equity compensation	(4,783)		(2,849)		(6,569)
Other	465		(620)		(1,093)
Provision for income taxes	$	76,825	$	78,393	$	102,053

Significant items comprising the Company's deferred tax assets and liabilities

The significant items comprising our deferred tax assets and liabilities as of September 30, 2019 and 2018 are as follows (in thousands):

	As of September 30,
	2019		2018
Net deferred tax assets/(liabilities)
Costs deductible in future periods	$	19,133	$	20,254
Deferred revenue	6,098		5,197
Stock compensation	3,617		3,469
Net operating loss carryforwards	798		302
Amortization of goodwill and intangible assets	(26,338)		(27,054)
Capitalized software	(8,635)		(6,016)
Accounts receivable - unbilled	(35,566)		(7,854)
Property and equipment	515		(2,011)
Prepaid expenses	(3,645)		(2,927)
Other	(2,351)		(2,903)
	$	(46,374)	$	(19,543)

Our deferred tax assets and liabilities are held in various national and international jurisdictions which do not allow right of offset. Accordingly, our presentation of deferred taxes on our consolidated balance sheets is split between jurisdictions which show a net deferred tax asset and a net deferred tax liability. Our net deferred tax position is summarized below (in thousands):

	As of September 30,
	2019		2018
Balance of tax jurisdictions with net deferred tax assets	$	186	$	6,834
Balance of tax jurisdictions with net deferred tax liabilities	(46,560)		(26,377)
Net deferred tax liabilities	$	(46,374)	$	(19,543)

Schedule of reconciliation of the beginning and ending amount of gross unrecognized tax benefits

The reconciliation of the beginning and ending amount of gross unrecognized tax benefits was as follows (in thousands):

	Year ended September 30,
	2019		2018		2017
Balance at beginning of year	$	721	$	633	$	448
Increases for tax positions taken in current year	2,280		88		185
Balance at end of year	$	3,001	$	721	$	633