Share Based Awards - RSUs and Bonus Plans (Details) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted					2,170,855
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Taxes paid for net settlement of stock-settled bonus					$ 5,492,000	$ 3,942,000
Stock-based compensation expense	$ 8,012,000		$ 9,380,000		$ 27,159,000	28,493,000
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, Beginning Balance		12,303,913			12,303,913
Granted					9,738,871
Vested					(6,075,000)
Cancelled/Forfeited					(2,161,696)
Unvested, Ending Balance	13,806,088				13,806,088
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested, Beginning Balance		$ 4.63			$ 4.63
Granted (in dollars per share)					5.45
Vested (in dollars per share)					4.75
Cancelled/Forfeited (in dollars per share)					4.71
Unvested, Ending Balance	$ 5.14				$ 5.14
Share withholding					1,064,577
2017 Bonus Plans
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Taxes paid for net settlement of stock-settled bonus				$ 3,700,000
Stock-based compensation expense						1,900,000
2017 Bonus Plans | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Common stock issued (in shares)				1,220,822
Share withholding				752,564
2018 Bonus Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Taxes paid for net settlement of stock-settled bonus		$ 4,100,000
Stock-based compensation expense			$ 2,000,000		$ 1,100,000	$ 6,500,000
2018 Bonus Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Common stock issued (in shares)		1,338,220
Share withholding		832,635
2019 Bonus Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Stock-based compensation expense	$ 559,000				$ 5,500,000
Stock-based compensation expense, prior period catch up	$ 1,200,000