Shareholders' Equity - CEO Performance Award - Additional Information (Details) $ in Thousands		3 Months Ended
	May 24, 2018 USD ($) tranche shares	Mar. 31, 2019 USD ($) 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
Total revenue		710,100
Adjusted EBITDA		125,000
Recorded share-based compensation expense		$ 4,700
Number of options expected to vest | shares		1,100,000
Weighted average period over which costs are recognized		7 years
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting tranches | tranche	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		$ 40,500
Unrecognized share-based compensation cost related to unvested stock option awards, not probable of achievement		$ 200,700