Summary of Significant Accounting Policies (Impact on Consolidated Balance Sheet Upon Adoption of ASC 842) (Detail) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Jul. 01, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018
Current assets:
Cash and cash equivalents	$ 167,771			$ 204,202	$ 230,700
Investments in marketable securities	7,754			8,680	8,341
Restricted cash	807			1,022	391
Accounts receivable, net	98,732			83,560	89,578
Prepaid expenses and other current assets	126,785			29,313	44,524
Total current assets	544,266			504,700	540,091
Noncurrent assets:
Property and equipment, net	286,346			283,433	279,387
Operating lease assets	188,629			0	0
Deferred income taxes	15,066			18,314	19,199
Intangible assets, net	290,092			297,989	237,013
Goodwill	686,235			687,256	627,685
Other assets, net	84,825			52,113	54,386
Total noncurrent assets	1,899,754			1,737,996	1,608,612
Total assets	2,444,020			2,242,696	2,148,703
Current liabilities:
Accounts payable	33,932			53,385	39,092
Accrued salaries, wages and benefits	40,373			46,664	39,439
Accrued liabilities	60,458			76,529	74,614
Deferred revenue	120,047			95,944	108,370
Current operating lease liabilities	51,926			0	0
Current portion of long-term debt	3,000			3,000	3,000
Total current liabilities	344,686			311,631	309,205
Noncurrent liabilities:
Long-term debt	446,610			398,094	288,589
Long-term operating lease liabilities	179,195			0	0
Deferred income taxes	28,147			29,426	33,278
Other liabilities	91,011			86,326	88,190
Total noncurrent liabilities	801,813			529,992	426,429
Total liabilities	1,146,499			841,623	735,634
Redeemable noncontrolling interest	2,962	$ 3,082		9,543	8,482	$ 8,651	$ 9,110
Shareholders' equity:
Common Stock, $0.01 Par Value	806			801	801
Additional paid-in capital	499,703			486,061	483,043
Retained earnings	2,183,620			2,012,902	1,964,169
Accumulated other comprehensive loss	(276,379)			(137,290)	(148,706)
Treasury Stock, at cost	(1,113,191)			(970,944)	(894,720)
Total shareholders' equity	1,294,559	$ 1,294,912		1,391,530	1,404,587	$ 1,429,647	$ 1,519,286
Total liabilities and shareholders' equity	$ 2,444,020			$ 2,242,696	$ 2,148,703
Common Stock, Par Value	$ 0.01		$ 0.01	$ 0.01	$ 0.01
ASC 842
Current assets:
Cash and cash equivalents			$ 299,445
Investments in marketable securities			8,680
Restricted cash			1,022
Accounts receivable, net			157,829
Prepaid expenses and other current assets			34,241
Total current assets			501,217
Noncurrent assets:
Property and equipment, net			364,683
Operating lease assets			282,978
Deferred income taxes			18,314
Intangible assets, net			418,097
Goodwill			874,451
Other assets, net			62,451
Total noncurrent assets			2,020,974
Total assets			2,522,191
Current liabilities:
Accounts payable			57,627
Accrued salaries, wages and benefits			64,492
Accrued liabilities			69,776
Deferred revenue			99,790
Current operating lease liabilities			66,707
Current portion of long-term debt			3,000
Total current liabilities			361,392
Noncurrent liabilities:
Long-term debt			398,094
Long-term operating lease liabilities			269,387
Deferred income taxes			29,426
Other liabilities			62,819
Total noncurrent liabilities			759,726
Total liabilities			1,121,118
Redeemable noncontrolling interest			9,543
Shareholders' equity:
Common Stock, $0.01 Par Value			801
Additional paid-in capital			486,061
Retained earnings			2,012,902
Accumulated other comprehensive loss			(137,290)
Treasury Stock, at cost			(970,944)
Total shareholders' equity			1,391,530
Total liabilities and shareholders' equity			2,522,191
ASC 842 | June 30, 2019
Current assets:
Cash and cash equivalents				$ 299,445
Investments in marketable securities				8,680
Restricted cash				1,022
Accounts receivable, net				157,829
Prepaid expenses and other current assets				37,724
Total current assets				504,700
Noncurrent assets:
Property and equipment, net				364,683
Deferred income taxes				18,314
Intangible assets, net				418,097
Goodwill				874,451
Other assets, net				62,451
Total noncurrent assets				1,737,996
Total assets				2,242,696
Current liabilities:
Accounts payable				57,627
Accrued salaries, wages and benefits				64,492
Accrued liabilities				86,722
Deferred revenue				99,790
Current portion of long-term debt				3,000
Total current liabilities				311,631
Noncurrent liabilities:
Long-term debt				398,094
Deferred income taxes				29,426
Other liabilities				102,472
Total noncurrent liabilities				529,992
Total liabilities				841,623
Redeemable noncontrolling interest				9,543
Shareholders' equity:
Common Stock, $0.01 Par Value				801
Additional paid-in capital				486,061
Retained earnings				2,012,902
Accumulated other comprehensive loss				(137,290)
Treasury Stock, at cost				(970,944)
Total shareholders' equity				1,391,530
Total liabilities and shareholders' equity				$ 2,242,696
ASC 842 | Adjustments due to adoption of ASC 842
Current assets:
Prepaid expenses and other current assets			(3,483)
Total current assets			(3,483)
Noncurrent assets:
Operating lease assets			282,978
Total noncurrent assets			282,978
Total assets			279,495
Current liabilities:
Accrued liabilities			(16,946)
Current operating lease liabilities			66,707
Total current liabilities			49,761
Noncurrent liabilities:
Long-term operating lease liabilities			269,387
Other liabilities			(39,653)
Total noncurrent liabilities			229,734
Total liabilities			279,495
Shareholders' equity:
Total liabilities and shareholders' equity			279,495
ASC 842 | Adjustments due to adoption of ASC 842 | Accrued Liabilities [Member]
Shareholders' equity:
Deferred rent liability, current			6,800
Restructuring liability, current			10,100
ASC 842 | Adjustments due to adoption of ASC 842 | Prepaid Expenses and Other Current Assets
Shareholders' equity:
Prepaid Rent			3,500
ASC 842 | Adjustments due to adoption of ASC 842 | Other Noncurrent Liabilities [Member]
Shareholders' equity:
Deferred rent liability, Noncurrent			24,800
Restructuring liability, Noncurrent			$ 14,900