Business Combinations - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	May 18, 2015	Feb. 17, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 615,433	$ 615,438			$ 493,890
LCS Corrections Services, Inc.
Business Acquisition [Line Items]
Accounts receivable and other current assets				$ 9,338
Prepaid expenses and other current assets				183
Property and equipment				119,726
Intangible assets				73,200
Total assets acquired				202,447
Accounts payable				2,442
Total identifiable net assets				200,005
Goodwill				107,398
Total consideration paid				$ 307,403
Soberlink, Inc
Business Acquisition [Line Items]
Accounts receivable and other current assets			$ 295
Inventory			385
Total assets acquired			15,880
Accounts payable			18
Deferred tax and other tax liabilities			5,670
Total identifiable net assets			10,192
Goodwill			14,210
Total consideration paid			24,402
Soberlink, Inc | Customer Relationships
Business Acquisition [Line Items]
Intangible assets			5,500
Soberlink, Inc | Technology
Business Acquisition [Line Items]
Intangible assets			$ 9,700