Stockholders' Equity - Common shares (Details) - shares		12 Months Ended
	Aug. 14, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of the beginning and ending common stock outstanding
Balance, beginning of year (shares)		116,417,000
Balance, end of year (shares)		125,132,000	116,417,000
Common Stock [Member]
Reconciliation of the beginning and ending common stock outstanding
Balance, beginning of year (shares)		116,416,900	101,517,009	98,828,098
Issuance of common stock (shares)	8,337,500	8,395,607	14,063,100	2,493,171
Non-vested stock-based awards, net of withheld shares and forfeitures (shares)		319,086	836,791	195,740
Balance, end of year (shares)		125,131,593	116,416,900	101,517,009