Organization, Consolidation and Presentation of Financial Statements - Additional Information (Detail) $ / shares in Units, Record in Millions								12 Months Ended
	Feb. 01, 2017 $ / shares	Jan. 01, 2017 USD ($)	Jun. 21, 2016 USD ($)	Jul. 22, 2015 USD ($) $ / shares shares	Jun. 24, 2015 USD ($) $ / shares shares	Mar. 18, 2015 USD ($) $ / shares shares	Mar. 03, 2015 USD ($)	Dec. 31, 2016 USD ($) Record Segment shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($)
Basis Of Presentation [Line Items]
ILEC, CLEC and VoIP records managed | Record								223
Sale of disposal group							$ 275,000,000
Proceeds from sale of property and equipment								$ 38,518,000	$ 303,000	$ 3,176,000
Gain loss on disposition of assets and leaseback transaction			$ 19,000,000
leaseback agreement period								P12Y
Deferred gain on sales-leaseback agreement								$ 5,200,000
Impairment of goodwill and intangible assets								$ 0	0
Number of operating segments | Segment								5
Impairments of finite-lived intangible assets								$ 0	0
Customer deposit								200,000	1,100,000
Deferred compensation liability								65,700,000	61,800,000
Uncertain tax positions								43,900,000	45,000,000
Deferred revenue noncurrent								38,700,000	60,000,000
Other long term liabilities								$ 21,000,000	$ 19,300,000
Common stock repurchased | shares					1,000,000	1,000,000		1,000,000	2,000,000
Aggregate share purchase price								$ 21,961,000	$ 59,957,000	0
Total dividend paid to shareholders								$ 74,700,000	75,200,000	75,700,000
Dividends Payable, Date to be Paid								Mar. 02, 2017
Dividends Payable, Date of Record								Feb. 21, 2017
Underwritten public offering common stock issued | shares				200,000	7,000,000	12,650,000
Underwritten public offering price per share | $ / shares				$ 30.75	$ 30.75	$ 30.75
Stock repurchased, price per share | $ / shares					$ 30.36	$ 29.596875
Aggregate purchase price of stock repurchased					$ 30,400,000	$ 29,600,000		$ 21,961,000	59,957,000
Proceeds from issuance of common stock				$ 0	$ 0	$ 0
Reclassification of other assets due to adoption of ASU standard								182,426,000	191,490,000
Reclassification of long-term debt due to adoption of ASU standard								3,129,963,000	3,318,688,000
Reclassification of accrued expenses due to adoption of ASU standard								224,871,000	219,234,000
Reclassification of increased deferred income due to adoption of ASU standard								88,864,000	104,222,000
Recently Implemented Accounting Pronouncements [Member] | Accounting Standard Update (“ASU”) 2015-03 [Member]
Basis Of Presentation [Line Items]
Reclassification of other assets due to adoption of ASU standard									57,100,000
Reclassification of long-term debt due to adoption of ASU standard									57,100,000
Recently Implemented Accounting Pronouncements [Member] | Accounting Standard Update (“ASU”) 2015-17 [Member]
Basis Of Presentation [Line Items]
Reclassification of accrued expenses due to adoption of ASU standard									1,700,000
Reclassification of increased deferred income due to adoption of ASU standard									1,700,000
Underwriters [Member]
Basis Of Presentation [Line Items]
Underwritten public offering common stock issued | shares				200,000	200,000	1,650,000
Subsequent Event [Member]
Basis Of Presentation [Line Items]
Per common share quarterly dividend | $ / shares	$ 0.225
Increase retained deficit		$ 100,000
Deferred Compensation Plan Mutual Fund Investments [Member]
Basis Of Presentation [Line Items]
Fair value with unrealized (losses) gains								2,700,000	$ (1,300,000)	$ 2,300,000
Maximum [Member]
Basis Of Presentation [Line Items]
Aggregate purchase price of stock repurchased								$ 75,000,000
Building [Member] | Minimum [Member]
Basis Of Presentation [Line Items]
Property, Plant and Equipment, Useful Life								20 years
Building [Member] | Maximum [Member]
Basis Of Presentation [Line Items]
Property, Plant and Equipment, Useful Life								39 years
Other Property Plant and Equipment [Member] | Minimum [Member]
Basis Of Presentation [Line Items]
Property, Plant and Equipment, Useful Life								3 years
Other Property Plant and Equipment [Member] | Maximum [Member]
Basis Of Presentation [Line Items]
Property, Plant and Equipment, Useful Life								5 years