Shareholders' Equity - CEO Performance Award - Additional Information (Details) $ in Thousands			9 Months Ended
	May 24, 2018 tranche shares	Feb. 26, 2018 tranche	Sep. 30, 2018 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
First tranche			$ 2,500,000
Tranche incremental increase			1,000,000
Revenue goal number 1			710,058
Revenue goal number 2			860,058
Revenue goal number 3			1,010,058
Revenue goal number 4			1,210,058
Revenue goal number 5			1,410,058
Revenue goal number 6			1,610,058
Revenue goal number 7			1,810,058
Revenue goal number 8			2,010,058
Adjusted EBITDA goal number 9			125,000
Adjusted EBITDA goal number 10			155,000
Adjusted EBITDA goal number 11			175,000
Adjusted EBITDA goal number 12			190,000
Adjusted EBITDA goal number 13			200,000
Adjusted EBITDA goal number 14			210,000
Adjusted EBITDA goal number 15			220,000
Adjusted EBITDA goal number 16			230,000
Adjusted EBITDA			125,000
Total revenue			710,100
Recorded share-based compensation expense			$ 1,800
Number of options, Options expected to vest, end of period (in shares) | shares			1,100,000
Weighted average period over which costs are recognized			8 years 3 months 14 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions [Abstract]
Risk free interest rate			2.98%
Expected term			10 years
Expected volatility rate			47.71%
Expected dividend yield			0.00%
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting tranches | tranche	12	12
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares authorized (in shares) | shares	6,365,856
Unrecognized share-based compensation cost related to unvested stock option awards, probable of achievement			$ 43,400
Unrecognized share-based compensation cost related to unvested stock option awards, not probable of achievement			$ 200,700