Subsequent Events - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended	6 Months Ended	0 Months Ended	1 Months Ended		1 Months Ended		0 Months Ended
	May 06, 2014	Jun. 30, 2014 Unsecured Credit Facility [Member]	Jul. 08, 2014 Subsequent Event [Member]	Aug. 31, 2014 Subsequent Event [Member]	Jul. 23, 2014 Subsequent Event [Member]	Aug. 31, 2014 Subsequent Event [Member] Unsecured Credit Facility [Member]	Aug. 31, 2014 Subsequent Event [Member] Richmond Credit Facility [Member]	Jul. 23, 2014 Subsequent Event [Member] Unsecured Credit Facility [Member]	Jul. 08, 2014 Subsequent Event [Member] Sun Times Press Facility [Member] sqft	Jul. 08, 2014 Subsequent Event [Member] Sun Times Press Facility [Member] Raised Floor With 24 MW Gross Power [Member] MW sqft	Jul. 08, 2014 Subsequent Event [Member] Sun Times Press Facility [Member] Raised Floor Capacity [Member] sqft	Jul. 08, 2014 Subsequent Event [Member] Sun Times Press Facility [Member] Raised Floor With 37 MW Gross Power [Member] MW sqft	Jul. 08, 2014 Subsequent Event [Member] Sun Times Press Facility [Member] Developable Land [Member] acre
Subsequent Event [Line Items]
Acquisition of data center facility									$ 18.0
Area of facility									317,000	134,000	400,000	215,000
Capacity of the plant										24		37
Area of real estate property													30
Cash dividend per common share	$ 0.29		$ 0.29	$ 0.29
Dividends Payable, Date Declared	Jul. 08, 2014		Jul. 08, 2014
Dividends Payable, Date of Record	Jun. 20, 2014		Jun. 20, 2014	Sep. 19, 2014
Aggregate principal amount					300
Senior notes due								2022
Interest rate of senior note		5.875%						5.875%
Percentage of issued price equal to face value					99.211%
Unsecured term loan outstanding					75
Dividends Payable, Date to be Paid				Oct. 07, 2014
Amount of unsecured revolving credit facility expanded						10	40
Current revolving Credit facility						$ 410	$ 120