Stockholders' Equity - Reconciliation of beginning and ending common stock outstanding (Details) - shares	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Reconciliation of the beginning and ending common stock outstanding
Balance, beginning of period	101,517,000
Balance, end of period	106,662,000	101,517,000
Common Stock [Member]
Reconciliation of the beginning and ending common stock outstanding
Balance, beginning of period	101,517,009	98,828,098
Issuance of common stock	4,838,115	2,493,171
Nonvested share-based awards, net	307,138	195,740
Balance, end of period	106,662,262	101,517,009