Segment Information - Financial Information by Major Geographic Area (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Total revenue		$ 256,396	$ 382,465	$ 324,747	$ 241,362	$ 251,671	$ 255,946	$ 317,035	$ 264,396	$ 1,204,970	$ 1,089,048	$ 1,064,987
Long-lived assets:
Total long-lived assets	[1]	324,155				226,870				324,155	226,870	220,845
United States
Revenue:
Total revenue										855,304	726,436	718,538
Long-lived assets:
Total long-lived assets	[1]	182,611				139,479				182,611	139,479	128,437
EMEA
Revenue:
Total revenue										205,028	220,046	192,674
Long-lived assets:
Total long-lived assets	[1]	37,083				15,714				37,083	15,714	14,215
Canada
Revenue:
Total revenue										144,638	142,566	153,775
Long-lived assets:
Total long-lived assets	[1]	$ 104,461				$ 71,677				$ 104,461	$ 71,677	$ 78,193

[1] In accordance with ASU 2015-03, unamortized debt issuance costs are reflected as a direct deduction from the carrying amount of the related debt. The Company adopted the new guidance retrospectively to all prior periods presented in the consolidated financial statements. As a result, $1.6 million and $2.0 million of unamortized debt issuance costs were reclassified from other investments and assets to a reduction of long-term debt on the December 31, 2015 and 2014 consolidated balance sheets, respectively.